Au Gratin Potatoes

Discover the ultimate comfort food side dish: Au Gratin Potatoes. With layers of thinly sliced potatoes, sweet onions, and a luxurious blend of two cheeses, this recipe is a guaranteed crowd-pleaser. Whether you’re hosting a grand holiday feast or simply craving a delicious accompaniment for your weeknight dinner, these creamy, cheesy potatoes are incredibly simple to make and can even be prepared ahead of time, taking the stress out of meal prep. Their rich flavor and irresistible texture make them the perfect complement to everything from succulent holiday ham or roasted turkey to a simple weeknight steak or pork chops.

Rave Reviews for Our Au Gratin Potatoes!

“This is so good. We added bacon to ours and it was like a baked potato.” – Lisa

Easy & Cheesy Au Gratin Potatoes: A Timeless Side Dish

This au gratin potatoes recipe might sound like a gourmet creation, something you’d expect to find on a fine dining menu. Yet, its beauty lies in its simplicity. Crafted from humble ingredients like potatoes, onions, a selection of cheeses, and common pantry staples, this dish transforms into an impressive culinary experience. It’s truly fascinating how such basic components can yield a side that is both elegant and profoundly satisfying.

While often used interchangeably, it’s worth noting the subtle differences between au gratin potatoes and scalloped potatoes. Both feature thinly sliced potatoes and onions baked to perfection. However, au gratin (from the French “au gratin,” meaning “with a crust”) traditionally includes a topping of breadcrumbs or cheese that creates a crispy, golden-brown crust. In contrast, scalloped potatoes typically rely on a rich cream or milk-based sauce without the distinct crusty topping. Our recipe embraces the best of both worlds, offering a creamy, cheesy interior with a beautifully bubbly, golden top layer.

The versatility of these au gratin potatoes is one of their greatest assets. They shine as a sophisticated holiday side dish, making any festive table feel complete. Yet, they are straightforward enough to whip up for a regular weeknight dinner, adding a touch of indulgence to an ordinary meal. For those looking to elevate the dish even further, consider incorporating diced cooked ham or crispy bacon crumbles – a fantastic way to transform them into a more substantial offering. And for busy cooks, the ultimate convenience: these potatoes can be assembled in advance, ready to bake when you are, making dinner preparation wonderfully stress-free.

Why You’ll Love This Au Gratin Recipe

Effortlessly Elegant: Despite its impressive appearance, this recipe is surprisingly easy to follow, making it accessible for home cooks of all skill levels.
Rich & Creamy: Layers of tender potatoes are bathed in a velvety cheese sauce, delivering comfort in every bite.
Perfectly Cheesy: A delightful combination of sharp cheddar and nutty Gruyère creates an irresistible flavor profile.
Versatile Pairing: It complements a wide array of main courses, from holiday roasts to everyday proteins.
Make-Ahead Friendly: Prepare it in advance to save time on busy days or during holiday cooking.
Crowd-Pleaser: This classic side dish is a guaranteed hit with family and friends, always disappearing quickly!

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5 from 6 reviews

Perfect Au Gratin Potatoes

Prep:

20

Cook:

1
15

Total:

1
35

Servings:

6
people

A spoon in a casserole dish of au gratin potatoes

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With thinly sliced potatoes, sweet onions, and a rich, creamy sauce made with two types of cheese, these simple Au Gratin Potatoes are an absolutely irresistible side dish. They pair beautifully with holiday ham or turkey, and are equally delightful alongside everyday favorites like pork chops or steak. An added bonus? This comforting casserole can be prepared in advance, making your meal planning much easier.

Step-by-step photos and detailed tips can be found below the recipe card for a flawless preparation!

Ingredients

6 medium russet potatoes, peeled and thinly sliced
1 small onion, sliced thin
¼ cup unsalted butter
¼ cup all-purpose flour
1½ cups whole milk
2 cups freshly shredded sharp cheddar cheese
1 tsp garlic powder
1 tsp salt
1 tsp black pepper
½ cup shredded Gruyère cheese, or additional cheddar cheese
Fresh chopped chives or parsley, for garnish (optional)

Instructions

Preheat your oven to 375°F (190°C). Prepare a 2-quart casserole pan by lightly coating it with nonstick cooking spray. This prevents sticking and ensures easy serving.
Carefully slice the peeled potatoes very thinly, aiming for no more than ⅛ inch thick. For best results and uniform slices, a mandoline slicer is highly recommended. This ensures even cooking and a beautiful presentation.
Arrange half of the thinly sliced potatoes in an even layer at the bottom of the prepared casserole pan. Distribute the sliced onions evenly over this potato layer. Then, top the onions with the remaining half of the sliced potatoes.
In a medium saucepan, melt the butter over medium heat. Once melted, gradually stir in the all-purpose flour to create a roux. Cook this mixture for 2 minutes, stirring continuously, until no white streaks of flour remain and it turns a pale golden color. Slowly whisk in the whole milk until the mixture is smooth and well combined, ensuring no lumps. Reduce heat to low, then stir in the cheddar cheese, garlic powder, salt, and pepper until the cheese has completely melted and the sauce is creamy. Pour this luscious cheese sauce evenly over the layered potatoes and onions in the casserole dish.
Ensure the cheese sauce is evenly distributed, covering all the potato layers for maximum flavor and moisture.
Cover the casserole pan tightly with aluminum foil to trap steam, which helps cook the potatoes thoroughly and prevents them from drying out. Bake for 45 minutes.
Remove the aluminum foil from the casserole dish. Evenly sprinkle the shredded Gruyère cheese over the top. Return the uncovered dish to the oven and bake for an additional 35-45 minutes, or until the top is beautifully golden brown, bubbly, and the potatoes are fork-tender.
Allow the au gratin potatoes to rest for 15 minutes after baking. This crucial step allows the sauce to thicken and set, making it much easier to cut and serve without falling apart. Garnish with fresh chopped parsley or chives for a touch of color and fresh flavor, then slice and serve warm!

Nutrition

Nutritional information provided is an automatic calculation and serves as an estimate. Values can vary significantly based on the exact products and brands used, as well as any modifications made to the recipe. If precise nutritional data is critical for your dietary needs, we recommend calculating them independently using your specific ingredients.

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Mastering Au Gratin Potatoes: Tips and Tricks

Choosing the Right Potatoes for Au Gratin

For the perfect au gratin, the choice of potato is crucial. Russet potatoes are highly recommended because their high starch content allows them to absorb the creamy sauce beautifully, resulting in a tender, melt-in-your-mouth texture. Yukon Gold potatoes are another excellent choice; they offer a slightly creamier texture and a naturally buttery flavor, holding their shape well while still becoming wonderfully tender. Avoid waxy potatoes like red or new potatoes, as they tend to hold too much moisture and can make the dish watery.

The Art of Thin Slicing

Uniformly thin potato slices are key to achieving even cooking and the signature tender texture of au gratin. Aim for slices no more than ⅛ inch thick. While a sharp chef’s knife can work with patience and skill, a mandoline slicer is truly your best friend here. It ensures consistent thickness across all slices, which is vital for the potatoes to cook through at the same rate. Always use the safety guard when operating a mandoline to protect your fingers.

Crafting the Perfect Cheese Sauce (Béchamel)

The velvety cheese sauce is the heart of this dish. It starts with a classic roux – equal parts butter and flour cooked together. This forms the base for a smooth, thick sauce. When adding the milk, do so slowly, whisking continuously to prevent lumps. Whole milk is preferred for its richness, contributing to a more luxurious texture. Once the milk is fully incorporated and the sauce begins to thicken, stir in your cheeses. Freshly shredded cheese melts much more smoothly and tastes better than pre-shredded varieties, which often contain anti-caking agents. Stir until completely melted and smooth, but avoid boiling the sauce vigorously once cheese is added, as this can cause it to separate.

Cheese Variations for a Custom Flavor

Our recipe uses a fantastic combination of sharp cheddar for its robust flavor and Gruyère for its nutty, complex notes and superior melting quality. However, don’t hesitate to experiment! Other cheeses that work wonderfully in au gratin include Fontina (for a creamy, mild, and nutty flavor), Parmesan (for a sharp, salty kick on top), Monterey Jack (for excellent meltiness), or even a blend of white cheddar and provolone. Choose cheeses that melt well and complement each other.

How to Make Au Gratin Potatoes: A Visual Guide

All ingredients laid out on a wooden board, including peeled russet potatoes, a small onion, butter, flour, milk, cheddar cheese, Gruyère cheese, and seasonings.

Step 1: Gather Ingredients and Prepare Your Pan
Begin by ensuring all your ingredients are measured and ready. Preheat your oven to 375°F (190°C) and lightly grease a 2-quart casserole pan with nonstick spray. This initial preparation ensures a smooth cooking process.

A mandoline slicer being used to thinly slice a russet potato on a wooden cutting board, producing even, uniform potato rounds.

Step 2: Expertly Slice the Potatoes
Achieving consistently thin slices is paramount for the perfect au gratin. Peel your russet potatoes and use a mandoline slicer to create uniform slices, no thicker than 1/8 inch. This critical step guarantees even cooking and a tender texture throughout the dish. While a very sharp knife can work, a mandoline simplifies this process considerably.

Layers of thinly sliced potatoes and onions arranged neatly in a white ceramic casserole dish, ready for the cheese sauce.

Step 3: Layer the Potatoes and Onions with Precision
In your prepared casserole dish, arrange half of the thinly sliced potatoes in an even layer. This forms the foundational layer. Next, distribute the finely sliced onions evenly over these potatoes, adding a subtle, savory depth. Finally, top the onions with the remaining half of the potato slices, completing the structured layers.

A creamy, golden cheese sauce being prepared in a saucepan on the stovetop, with butter, flour, milk, and shredded cheese melting together.

Step 4: Create the Rich Cheese Sauce
In a medium saucepan, melt ¼ cup of butter. Gradually whisk in ¼ cup of all-purpose flour, cooking for two minutes to create a roux, which will thicken your sauce. Slowly pour in 1½ cups of whole milk, whisking continuously until smooth and combined. Reduce the heat and stir in 2 cups of shredded sharp cheddar cheese, 1 teaspoon of garlic powder, 1 teaspoon of salt, and 1 teaspoon of black pepper. Continue stirring until the cheese is fully melted and the sauce is lusciously creamy. Pour this decadent sauce evenly over the layered potatoes and onions in your casserole dish, ensuring every crevice is filled with cheesy goodness.

A white casserole dish filled with au gratin potatoes, covered tightly with aluminum foil, ready for the initial baking stage.

Step 5: Bake for Tenderness and Flavor Infusion
Cover your casserole pan tightly with aluminum foil. This helps to steam the potatoes, ensuring they cook through and become perfectly tender while preventing the top from browning too quickly. Bake the covered dish in the preheated oven at 375°F (190°C) for 45 minutes. This initial baking period is crucial for softening the potatoes.

Step 6: Achieve Golden Perfection with More Cheese
After 45 minutes, carefully remove the aluminum foil. Sprinkle ½ cup of shredded Gruyère cheese (or more cheddar if you prefer) evenly over the top of the potatoes. Return the uncovered casserole dish to the oven and continue baking for another 35 to 45 minutes. Watch as the top turns a beautiful golden brown and the cheese sauce becomes visibly bubbly and irresistible. The potatoes should be completely fork-tender.

An overhead shot of a freshly baked casserole dish of au gratin potatoes, golden brown and bubbling with melted cheese and a sprinkle of fresh herbs.

Step 7: Rest, Garnish, and Serve
Once baked to perfection, remove the au gratin potatoes from the oven. Let them rest for 15 minutes before serving. This resting period is essential; it allows the rich cheese sauce to thicken and set, making it much easier to cut neat, appealing slices. Before serving, garnish with a sprinkle of fresh chopped parsley or chives for a burst of color and fresh flavor. Then, simply slice into generous portions and enjoy this delectable side dish!

Make-Ahead, Storage, and Reheating Tips

One of the fantastic advantages of these au gratin potatoes is their make-ahead potential, which is incredibly helpful for busy schedules or holiday meal prep. To prepare in advance, simply assemble the entire dish up to the point of baking, covering it tightly with plastic wrap or aluminum foil. Store it in the refrigerator for up to 24 hours. When you’re ready to bake, let the casserole sit on the counter for 15-20 minutes to come closer to room temperature before placing it in the oven. You may need to add an extra 10-15 minutes to the initial covered baking time if starting from cold.

Should you find yourself with any delicious leftovers (a rare occurrence!), ensure they are stored properly. Transfer any remaining au gratin potatoes to an airtight container and refrigerate them for up to 4 days. This ensures they retain their freshness and flavor.

Reheating is simple. For a whole pan of leftovers, cover it with aluminum foil and reheat in a preheated oven at 350°F (175°C) until warmed through, about 20-30 minutes. For individual servings, the microwave works perfectly; simply heat in short bursts until hot, stirring occasionally to distribute the warmth evenly. A quick tip for reheating: a splash of milk or cream can help restore some of the original creaminess if the sauce appears too thick.

A close-up of a serving spoon holding a portion of creamy au gratin potatoes, showing the layered texture and rich cheese sauce.

Perfect Pairings: What to Serve With Au Gratin Potatoes

Au gratin potatoes are a remarkably versatile side dish, capable of elevating both grand holiday feasts and simple weeknight meals. Their rich, creamy, and cheesy profile makes them an ideal companion to a wide array of main courses.

Holiday Staples: They are an absolute showstopper alongside festive holiday roasts. Imagine them complementing a beautifully cooked honey-orange glazed spiral ham, a succulent roasted turkey with crispy skin, or a tender prime rib. The potatoes provide a comforting richness that balances the flavors of your main protein perfectly.
Hearty Weeknight Dinners: Don’t reserve this dish just for special occasions! It’s easy enough to prepare for any weeknight. Pair it with a juicy marinated steak, these tender air fryer pork chops, or a perfectly baked chicken breast. The creamy potatoes add a luxurious element to everyday proteins, making even a simple meal feel special.
Other Delicious Options: Consider serving them with pan-seared salmon for a balanced meal, alongside roasted vegetables like asparagus or green beans for a complete plate, or even as a comforting side to meatloaf or pot roast. Their versatility truly knows no bounds.

More Irresistible Potato Side Dishes to Explore

If you’re a potato lover, there’s a whole world of delicious side dishes waiting to be discovered. Potatoes are incredibly versatile, offering endless possibilities for comforting and satisfying meals. If you enjoyed these au gratin potatoes, you might also love these other fantastic potato recipes:

Air Fryer Baked Potatoes: Crispy skin, fluffy interior, baked to perfection in your air fryer for a quick and easy classic.
Potato Knish: Savory mashed potatoes encased in a tender, flaky dough, a delicious traditional treat.
Oven Roasted Potatoes: Simple yet utterly delicious, these potatoes are tossed with herbs and roasted until golden and crispy.
Cheesy Potatoes: A classic comfort dish featuring diced potatoes baked in a rich, creamy cheese sauce, often with a crunchy topping.
Best Mashed Potatoes: Velvety smooth and incredibly flavorful, these are the ultimate mashed potatoes for any occasion.

Frequently Asked Questions About Au Gratin Potatoes

What type of potatoes are best for au gratin?

Russet potatoes are typically considered the best due to their high starch content, which helps them absorb the creamy sauce beautifully and become wonderfully tender. Yukon Gold potatoes are also an excellent choice, offering a buttery flavor and creamy texture.

Do I need a mandoline slicer for au gratin potatoes?

While not strictly necessary, a mandoline slicer is highly recommended. It ensures consistent, very thin slices (about ⅛ inch thick), which is crucial for even cooking and the signature texture of au gratin. If using a knife, take extra care to slice the potatoes as uniformly as possible.

Can I make au gratin potatoes ahead of time?

Yes, absolutely! You can assemble the entire casserole up to 24 hours in advance. Cover it tightly and refrigerate. Before baking, allow it to sit at room temperature for 15-20 minutes, and you might need to add a few extra minutes to the initial covered baking time.

How do I prevent my au gratin potatoes from being watery?

Ensure your potato slices are thin and even for proper cooking. Using starchy potatoes (like Russets) helps absorb moisture. Also, make sure your cheese sauce is adequately thickened with the roux. Allowing the dish to rest for 15 minutes after baking is also crucial, as the sauce will continue to thicken as it cools.

What’s the difference between au gratin and scalloped potatoes?

Both feature sliced potatoes, but au gratin typically includes cheese and often a crispy topping (like breadcrumbs or more cheese, creating a “gratin” crust). Scalloped potatoes usually have a creamy sauce but traditionally no cheese or crusty topping, focusing more on the layered potato and cream texture.

Can I add meat to au gratin potatoes?

Yes! Adding diced cooked ham, crispy bacon bits, or even shredded chicken can transform au gratin potatoes into a more hearty main dish. Stir them into the potato layers before pouring the sauce over.

We hope you enjoy creating and savoring this delightful Au Gratin Potatoes recipe. It’s truly a testament to how simple ingredients can come together to create something extraordinary and comforting. Happy cooking!