Au Gratin Potatoes Recipe - The Cookie Rookie® (2024)

Au Gratin Potatoes are a stunning side dish that always earns a spot on my holiday lineup! Thinly sliced potatoes and onions baked in a rich, creamy sauce with a delicious cheesy crust will have the whole family smitten. I mean…just take a look at that sauce.

What’s in This Au Gratin Potatoes Recipe?

This potatoes au gratin recipe uses simple household ingredients and will go from kitchen to table in just a few easy steps! If there’s one recipe that I am guaranteed to be making every holiday; Thanksgiving, Christmas, and Easter, it’s this one.

• Potatoes: We use Yukon gold potatoes in this recipe. They hold their shape wonderfully and don’t require peeling, making prep time a breeze.
• Onion: Yellow onions work best since they have a natural sweetness that compliments the rest of the dish.
• Butter: Unsalted butter is best to avoid a salty taste. However, salted butter may be used if preferred.
• Garlic: Fresh garlic is best, but pre-minced can be used in a pinch.
• Flour: All-purpose flour works best. For gluten-free au gratin potatoes, swap the all-purpose flour for an equal amount of gluten-free 1:1 flour.
• Milk: Whole milk helps to create the best cheesy, decadent consistency. Try not to substitute this with any other dairy product!
• Cheese: Shred your own cheddar, gruyere, and Parmesan cheese from a block for the smoothest sauce. Pre-shredded cheese is coated in starches that can cause the sauce to become grainy!

Variations on Potatoes Au Gratin

• You can use red potatoes in place of Yukon Gold.
• Feel free to switch up the cheese. Some other great cheeses include Swiss, fontina, Havarti, gouda, or mozzarella.
• Try adding 6-8 ounces of chopped cooked bacon or ham!
• Try adding 1-2 teaspoons of fresh herbs to the cheese sauce.
• Try topping your casserole with breadcrumbs or crumbled Ritz crackers.

How to Store and Reheat

Store leftover au gratin potatoes in an airtight container in the refrigerator for up to 5 days. Reheat in a 350°F oven covered with foil for about 20 minutes, or until hot.

How to Freeze

Freeze au gratin potatoes in individual portions in airtight containers for up to 2 weeks. Let thaw overnight in the refrigerator before reheating.

Serving Suggestions

Potatoes au gratinare the ultimate creamy and cheesy side dish for Thanksgiving, Christmas, Easter, or any holiday. They pair nicely with turkey, ham, beef tenderloin, or any other holiday main dish you serve.

Notes from the Test Kitchen

If you’re short on time, wrap the baking pan (non-metal only!) in plastic wrap before adding the cheese sauce, microwave on high for 10 minutes, remove the plastic wrap, add the cheese sauce, and bake as directed for about 40-45 minutes.

How to Make Au Gratin Potatoes Step by Step

Layer the Potatoes and Onions: Preheat oven to 350°F. Grease a 9×13-inch baking pan with butter. Layer 3 pounds of thinly sliced Yukon Gold potatoes ½ of a thinly sliced yellow onion in the baking dish. Set aside.

Melt the Butter: In a medium saucepan, melt 4 tablespoons of unsalted butter over medium heat. Add in 2 cloves of minced garlic and cook until fragrant.

Thicken the Roux: Sprinkle over ¼ cup of all-purpose flour and whisk until smooth and the flour is golden, about 1 minute.

Thin the Sauce: Slowly pour in 1½ cups of whole milk while whisking, making sure to quickly whisk out any lumps. Bring to a simmer.

Add the Cheese: Remove from the heat and whisk in 1 teaspoon of kosher salt, ½ teaspoon of ground black pepper, 1 cup of shredded cheddar, and ¾ cup of shredded gruyere until melted. Pour over the potatoes.

Bake the Casserole: Cover with foil and bake for 45-60 minutes, or until the potatoes are tender when pierced with a knife in the center of the baking dish.

Brown the Casserole: Remove the foil and sprinkle on the remaining ¾ cup of shredded gruyere and ½ cup of grated parmesan cheese. Bake for 15-20 minutes until the cheese is melted and bubbly. To brown the cheese, broil for 1-2 minutes. Garnish with herbs and serve.

More Holiday Side Dish Recipes We Love

• Parmesan Creamed Potatoes
• Butternut Squash Stuffing
• Chantilly Potatoes
• Crockpot Green Bean Casserole
• Instant Pot Sweet Potato Casserole
• Roasted Butternut Squash
• Loaded Scalloped Potatoes