Name: Au Gratin Potatoes
Prep time: 20 min
Cook time: 65 min
Total time: 85 min
Ingredients: 4 large russet potatoes (peeled and thinly sliced); 1 large yellow onion (thinly sliced); 3 Tablespoons butter; 3 Tablespoons all-purpose flour; 2 cups heavy cream; 1 teaspoon salt; 1/2 teaspoon black pepper; 1/2 teaspoon garlic powder; 1 1/2 cups shredded cheddar cheese; 1 1/2 cups shredded Gruyère cheese (divided); Fresh parsley or chives (chopped, for garnish)

By: Jill Mills Updated: Dec 31, 2024

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Thinly sliced potatoes and onions are topped with a creamy and decadent cheese sauce in this Au Gratin Potatoes recipe. A combination of Gruyère and cheddar cheese adds the most incredible flavor.

A spoon serving au gratin potatoes from the baking dish

In this house, we love cheese and we love potatoes. So, naturally, this au gratin potatoes recipe is a hit every single time I make it. In fact, it may be one of the most requested side dishes at this point. It’s creamy, cheesy, and the potatoes are so incredibly tender after they’ve baked. Definitely a dish to add to the holiday menu!

Why You’ll Love This Au Gratin Potatoes Recipe

Here are a few reasons why we love this side dish.

Only 20 minutes of hands-on time. While the total time for this recipe is an hour and 25 minutes, most of that time is hands-off baking time. The hands-on prep is quick and easy.
Super decadent and cheesy. The sauce for these potatoes is INCREDIBLE. It’s thick, creamy, and super cheesy. The combination of cheddar and Gruyère adds the best flavor.
Great for the holidays. I love serving these au gratin potatoes as a holiday side. They’re always a hit and one of the first things to disappear.

Overhead view of a plate of au gratin potatoes

Au Gratin vs Scalloped Potatoes

Scalloped potatoes and au gratin potatoes are different, though sometimes the terms are used interchangeably. Technically speaking, au gratin potatoes are made with a cheese sauce while scalloped potatoes are made without cheese. But many versions of scalloped potatoes, including mine, are made with cheese as well.

The main difference between my two recipes is that these au gratin potatoes are made with multiple types of cheese and there’s one layer of potatoes, one layer of onions, and the cheese sauce. They’re both delicious!

Overhead view of ingredients needed to make Au Gratin Potatoes

Recipe Ingredients

You’ll need potatoes, onions, cheese, and just a few other basic ingredients to make this side dish. Scroll down to the recipe card below for the exact measurements.

Russet potatoes – While russet potatoes are ideal for this recipe due to their starchy texture, Yukon Gold potatoes can be used for a slightly buttery flavor and creamy texture.
Yellow onion – If you’re not a fan of yellow onions, try using sweet onions for a milder taste or shallots for a more delicate flavor.
Butter – Adds a richness to the recipe.
Flour – For making the roux.
Heavy cream – Creates the rich, creamy base of the cheese sauce. For a lighter version, consider using half-and-half instead of heavy cream. Note that the sauce may not be as thick.
Spices – Salt, pepper, and garlic powder.
Cheese – A combination of shredded cheddar and Gruyère for the best flavor and texture. Freshly shredded cheese does so much better in this recipe than packaged cheese. If Gruyère cheese is not available, you can substitute it with Swiss cheese for a similar flavor profile.
Fresh parsley – For garnish. Chives work well too.

How To Make Au Gratin Potatoes

The great part of this recipe is that the hands-on time is just 20 minutes or so. You can find the printable version of the instructions in the recipe card below.

Spices added to a cream sauce in a skillet

Make the sauce. Melt the butter over medium heat then whisk in 3 tablespoons of flour, whisking for 1 minute until smooth and bubbly. Slowly whisk in the heavy cream. Cook for 5-7 minutes, stirring constantly, until it thickens and bubbles.
Add the cheese. Stir in the seasonings. Reduce the heat to low and stir in the cheese (except 1/2 cup of the Gruyère) until melted and smooth.

Rows of sliced potatoes in a baking dish

Sliced onion on top of potatoes in a baking dish

Assemble. Grease the baking dish. Arrange the potatoes in overlapping rows then top with the sliced onions. Pour the cheese sauce evenly over the top then sprinkle the remaining cheese over the sauce.
Bake. Cover the pan with foil. Bake for 40 minutes then remove the foil and bake for an additional 20-25 minutes. The top should be golden brown and the potatoes should be tender.
Enjoy. Let the potatoes cool for a few minutes then garnish with the freshly chopped parsley or chives.

Overhead view of au gratin potatoes in a baking dish

Tips for Success

Here are a few key tips to making the best au gratin potatoes.

Slice everything very thin. Both the potatoes and the onions need to be in thin slices. If they’re too thick, they won’t finish cooking in time. I recommend using a mandolin to help achieve consistent thin slices.
Don’t boil the cheese sauce. Before you add the cheese, be sure to reduce the heat. If it’s too hot, the cheese will separate instead of melting into the sauce.
Use freshly shredded cheese. You can use the packages of shredded cheese but freshly shredded cheese melts so much better. The texture of the sauce will be smoother and creamier.
Try other types of cheese. You can experiment with other types of cheese in this recipe but I recommend using at least 2 different types and choosing ones with bold flavors. Swiss, provolone, and parmesan are all good additions. Just make sure the total amount of cheese used is always 3 cups.

A fork in an au gratin potato on a black plate

What To Serve Them With

Au gratin potatoes are one of those side dishes that pair with everything from a casual weeknight dinner to a holiday meal. Some of my favorite entrees to serve these with include prime rib, eye of round roast, and pork tenderloin. They’re also great with Christmas ham and Thanksgiving turkey.

How To Store & Reheat Leftovers

Fridge. Leftover au gratin potatoes can be stored in an airtight container in the refrigerator for up to 3 days.
Freezer. To freeze, allow the dish to cool completely, then cover tightly with plastic wrap and foil. Freeze for up to 2 months. Thaw in the refrigerator overnight before reheating.
Reheat. To reheat, cover with foil and warm in a 350°F (175°C) oven until heated through. Individual servings can be reheated in the microwave as well.

Au Gratin Potatoes