This post may contain affiliate links. See our Privacy Policy.
Potatoes au gratin is a comforting, creamy side dish that never goes out of style. Thinly sliced potatoes are layered with a rich white sauce, plenty of cheese, and baked until bubbly with a golden, buttery breadcrumb topping. This version uses classic cheddar, but you can elevate the dish with Swiss or Gruyère for added depth.
Whether you’re serving it for the holidays or a weeknight family meal, this gratin is a welcome companion to roast meats, poultry, or ham—and the leftovers are just as delicious.
What You’ll Like About This Dish
Creamy and cheesy. A smooth white sauce and layers of melted cheese give the gratin a luxurious texture.
Classic comfort. Baked until bubbly and topped with a buttery, crisp topping—it’s always a hit.
Customizable flavors. Easy to enhance with herbs, alternate cheeses, or protein add-ins.
Ingredient Notes
- Potatoes: Use starchy baking potatoes like Russets for the best creamy texture; slice them thinly for even cooking.
- Butter: Divided between the white sauce and the breadcrumb topping.
- Flour: Forms a roux to thicken the sauce.
- Milk or cream: Half-and-half or light cream adds richness, but whole milk works too.
- Cheddar cheese: Classic choice for flavor and meltability; reserve some for the topping.
- Nutmeg: Just a pinch adds warmth and depth to the cream sauce.
- Salt and pepper: Season to taste once the sauce is finished.
- Breadcrumbs: Use soft fresh crumbs for the best topping texture.
Steps to Make Potatoes Au Gratin
- Preheat oven to 375°F and butter a 2-quart baking dish.
- Melt 4 tablespoons of butter in a saucepan and stir in the flour.
- Whisk in the milk or cream gradually and cook until thickened and bubbling.
- Add nutmeg, salt, and pepper to taste; stir in 1½ cups of cheese until melted.
- Layer half the potato slices in the dish and spoon over half the sauce.
- Repeat with remaining potatoes and sauce.
- Bake for 1 hour, uncovered.
- Mix remaining 2 tablespoons of melted butter with breadcrumbs and remaining cheese.
- Sprinkle topping over the gratin and bake 15 to 20 minutes more, until golden and bubbling.
Tips for Gratin Success
- Slice potatoes evenly and thinly—about 1/8 inch—for uniform baking.
- Use a mandoline for faster prep and consistent thickness.
- Don’t skip seasoning—taste the sauce before layering.
- If using milk only, simmer a bit longer for a thicker sauce.
- Let gratin rest for 5 to 10 minutes before serving for easier slicing.
Recipe Variations
- Cheese: Elevate the dish with Gruyère cheese or Swiss in the sauce and topping instead of cheddar.
- Herbs: Add chopped fresh parsley or chives to the sauce for a pop of color.
- Protein: Add some diced cooked bacon or ham to the potato layers for smoky flavor and extra protein.
- Vegetables: Layering thinly sliced shallots, leeks, or onions with the potatoes can add flavor and texture. Or sauté 1/4 to 1/2 cup of chopped shallots in the butter before adding the flour.
Serving Suggestions
- Serve with baked ham, roast beef, or pork tenderloin.
- Pair with roasted chicken and a green vegetable for a complete meal.
- Add to a holiday spread alongside stuffing and cranberry sauce.
- Include as a hearty side for vegetarian mains.
- Offer warm from the oven with crusty bread and salad.
How to Store and Reheat
Refrigerate: Cover tightly and refrigerate leftovers for up to 4 days. Let cool completely before storing.
Freeze: Not ideal—the sauce may separate, and the texture may change. If freezing, wrap well and reheat gently from thawed.
Reheat: Warm in a 350°F oven until hot and bubbly. Cover loosely with foil to prevent over-browning. Individual portions can be microwaved or reheated in a toaster oven.
Potatoes Au Gratin
Ingredients
- Butter, for greasing the baking dish
- 6 tbsp butter, divided
- 3 tbsp all-purpose flour
- 2 cups half-and-half or milk
- ⅛ tsp ground nutmeg, or to taste
- 2 cups shredded cheddar cheese, divided
- Kosher salt and freshly ground black pepper, to taste
- 2 pounds russet or gold potatoes, peeled and thinly sliced, about 1/8-inch thickness
- 1 cup fresh breadcrumbs
Recommended Equipment
- Mandoline Slicer optional, but an excellent tool for slicing the potatoes thinly and uniformly
Instructions
- Preheat the oven to 375°F.
- Butter a 2 1/2-quart baking dish.Butter
- Melt 4 tablespoons of butter in a medium saucepan over medium heat. Stir in the flour and cook, stirring, for about 1 minute. Gradually whisk in the half-and-half or milk. Add the nutmeg and cook, stirring constantly, until the sauce thickens and bubbles. Add 1 1/2 cups of the shredded cheese; stir until the cheese is melted. If the sauce is too thick, add a splash more half-and-half or milk. Taste the sauce and add salt and pepper as needed.4 tbsp butter | 3 tbsp all-purpose flour | 2 cups half-and-half or milk | 1/8 tsp ground nutmeg | 1 ½ cups shredded cheddar cheese | Kosher salt and freshly ground black pepper
- Arrange half of the potato slices in the baking dish.2 pounds russet or gold potatoes
- Spoon half of the sauce over the potato layer, then follow with the remaining potatoes. Spoon the remaining sauce over the top.
- Bake for 1 hour.
- If the top starts to brown before the potatoes are tender, cover the dish loosely with foil.
- Melt the remaining 2 tablespoons of butter and toss with the breadcrumbs and the remaining 1/2 cup of cheese.2 tbsp butter | 1 cup fresh breadcrumbs | ½ cups shredded cheddar cheese
- Remove the casserole from the oven and sprinkle with the breadcrumb-cheese mixture.
- Return the potato gratin to the oven and bake for 15 to 20 minutes longer, or until the topping is browned and the potatoes are tender when pierced with a knife.
Nutrition
Disclaimer:
Our nutritional information is based on a third-party application that analyzes the ingredients list to determine the values. The information is meant to be helpful, but should be considered an estimate. Values may differ depending on measurements, brands, serving variations, and database availability.
