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.
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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.
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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 gratin are 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.
Au Gratin Potatoes Recipe
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Ingredients
- 3 pounds Yukon Gold potatoes thinly sliced (about 12 potatoes)
- ½ yellow onion thinly sliced
- 4 tablespoons unsalted butter (½ stick) plus more for greasing the pan
- 2 cloves garlic minced
- ¼ cup all-purpose flour
- 1½ cups whole milk
- 1 teaspoon kosher salt
- ½ teaspoon ground black pepper
- 1 cup freshly shredded cheddar cheese
- 1½ cups freshly shredded gruyere cheese divided
- ½ cup freshly grated Parmesan cheese
Recommended Equipment
Instructions
- Preheat oven to 350°F. Grease a 9×13-inch baking pan with butter.
- Layer the potatoes and onions in the baking dish. Set aside.3 pounds Yukon Gold potatoes, ½ yellow onion
- In a medium saucepan, melt the butter over medium heat. Add in the garlic and cook until fragrant.4 tablespoons unsalted butter, 2 cloves garlic
- Sprinkle over the flour and whisk until smooth and the flour is golden, about 1 minute.¼ cup all-purpose flour
- Slowly pour in the milk while whisking, making sure to quickly whisk out any lumps. Bring to a simmer.1½ cups whole milk
- Remove from the heat and whisk in the salt, pepper, cheddar, and ¾ cup gruyere until melted. Pour over the potatoes.1 teaspoon kosher salt, ½ teaspoon ground black pepper, 1 cup freshly shredded cheddar cheese, 1½ cups freshly shredded gruyere cheese
- 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.
- Remove the foil and sprinkle on the remaining gruyere and parmesan cheese. Bake for 15-20 minutes until the cheese is melted and bubbly.½ cup freshly grated Parmesan cheese
- Optional: To brown the cheese, broil for 1-2 minutes.
- Garnish with herbs and serve.
Last step! Don’t forget to show me a pic of what you made! Upload an image or tag me @thecookierookie on Instagram!
Becky’s tips
- Take care to slice the potatoes into even ⅛-inch thick slices; use a mandoline or food processor for easy even slices!
- Don’t pack in the potatoes and onions too tightly. You want to leave enough space for the cheese to penetrate all the way through.
- Shred your own cheese from a block for the smoothest sauce. Pre-shredded cheese is coated in starches that can cause the sauce to become grainy!
Nutrition Information
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.
Au gratin potatoes are a much more decadent version of scalloped potatoes because they include the addition of cheese! Scalloped potatoes are baked in a basic cream sauce, while au gratin potatoes are made with cheese both in between the layers and on top!
“Au gratin” basically means covered with breadcrumbs or grated cheese and browned. It refers to the bubbly, crispy cheese topping!
