Potatoes au gratin is a timeless, comforting side dish of thinly sliced potatoes layered in a velvety white sauce, topped with melted cheese and baked until bubbly. A crisp, buttery breadcrumb topping adds contrast. This version features cheddar for classic flavor; swap in Swiss or Gruyère for a nuttier, more complex profile.
Perfect for holiday menus or weeknight dinners, this gratin pairs beautifully with roast meats, poultry, or ham. Leftovers reheat well and are just as satisfying.
What You’ll Like About This Dish
Creamy and cheesy. A smooth white sauce combined with melted cheese creates a rich, luxurious texture.
Comfort food classic. Baked until bubbling and finished with a golden, crisp topping—always a crowd-pleaser.
Easy to customize. Add herbs, different cheeses, or cooked proteins to tailor the dish to your tastes.
Ingredient Notes
- Potatoes: Use starchy baking potatoes like russets for a creamy result; slice about 1/8 inch thick for even cooking.
- Butter: Divided between the sauce and the breadcrumb topping for flavor and richness.
- Flour: Forms a roux to thicken the sauce.
- Milk or cream: Half-and-half or light cream makes a richer sauce; whole milk works if you prefer a lighter version.
- Cheddar cheese: A reliable melting cheese with good flavor; reserve some for the topping.
- Nutmeg: A tiny pinch brightens the cream sauce without being obvious.
- Salt and pepper: Season to taste after the sauce has thickened.
- Breadcrumbs: Fresh or soft breadcrumbs give the topping the best texture.
Steps to Make Potatoes Au Gratin
- Preheat the oven to 375°F (190°C) and butter a 2 to 2 1/2‑quart (or similar) baking dish.
- Melt 4 tablespoons butter in a medium saucepan over medium heat, stir in 3 tablespoons flour and cook for about 1 minute to form a roux.
- Gradually whisk in 2 cups half-and-half or milk. Cook, stirring, until the sauce thickens and begins to bubble.
- Add 1/8 teaspoon nutmeg, then season with salt and pepper. Stir in 1½ cups shredded cheddar until melted; thin with a splash more milk if needed.
- Arrange half the potato slices in the prepared dish and spoon half the sauce over them.
- Top with the remaining potato slices and pour the remaining sauce over the top.
- Bake uncovered for 1 hour. If the top browns too quickly before the potatoes are tender, cover loosely with foil.
- Melt the remaining 2 tablespoons butter and toss with 1 cup fresh breadcrumbs and the remaining 1/2 cup shredded cheese.
- Remove the gratin from the oven, sprinkle the breadcrumb-cheese mixture over the top, and return to the oven for 15–20 minutes more, until the topping is golden and the potatoes are easily pierced with a knife.
Tips for Gratin Success
- Slice potatoes evenly—about 1/8 inch—to ensure uniform doneness.
- A mandoline speeds prep and guarantees consistent thickness.
- Taste and season the sauce before layering so the finished dish is well seasoned.
- If using only milk, simmer the sauce a little longer to reach the desired thickness.
- Allow the gratin to rest 5–10 minutes before serving to make slicing easier and to let the sauce settle.
Recipe Variations
- Cheese: Substitute Gruyère or Swiss for a richer, nuttier flavor.
- Herbs: Fold in chopped fresh parsley, chives, or thyme for brightness.
- Protein: Add cooked diced bacon or ham between the layers for a smoky, savory boost.
- Vegetables: Layer thinly sliced shallots, leeks, or onions with the potatoes, or sauté 1/4–1/2 cup chopped shallots in the butter before making the roux.
Serving Suggestions
- Serve alongside baked ham, roast beef, or pork tenderloin.
- Pair with roasted chicken and a green vegetable for a balanced meal.
- Add to a holiday table with stuffing and cranberry sauce.
- Include as a hearty side for vegetarian mains.
- Offer warm from the oven with crusty bread and a simple salad.
How to Store and Reheat
Refrigerate: Cool completely, cover tightly, and store leftovers in the refrigerator for up to 4 days.
Freeze: Freezing is not ideal because the sauce texture may change. If you must freeze, wrap well and thaw completely before reheating.
Reheat: Warm in a 350°F (175°C) oven until hot and bubbly, covering loosely with foil to prevent over-browning. Individual portions can be reheated in a microwave or toaster oven.
Potatoes Au Gratin
6 servings
561
Ingredients
- Butter, for greasing the baking dish
- 6 tbsp butter, divided
- 3 tbsp all-purpose flour
- 2 cups half-and-half or milk
- 1/8 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)
- 1 cup fresh breadcrumbs
Recommended Equipment
- Mandoline slicer (optional, for uniform slices)
- Medium saucepan
- 2 to 2 1/2‑quart baking dish
Instructions
- Preheat the oven to 375°F (190°C).
- Butter a 2 to 2 1/2‑quart baking dish.
- Melt 4 tbsp butter in a medium saucepan over medium heat. Stir in 3 tbsp flour and cook for about 1 minute. Gradually whisk in 2 cups half-and-half or milk. Add 1/8 tsp nutmeg and cook, stirring, until the sauce thickens and bubbles. Stir in 1½ cups shredded cheddar until melted. Taste and season with salt and pepper. Thin with a little more milk if necessary.
- Arrange half of the potato slices in the baking dish, then spoon half the sauce over the potatoes.
- Add the remaining potatoes and pour the remaining sauce over the top.
- Bake uncovered for 1 hour. If the top browns before the potatoes are tender, cover loosely with foil.
- Melt the remaining 2 tbsp butter and combine with 1 cup breadcrumbs and the remaining 1/2 cup cheese. Sprinkle over the gratin.
- Return to the oven and bake 15–20 minutes more, until the topping is golden and the potatoes are tender when pierced.
Nutrition
Disclaimer:
Nutrition facts are estimates based on the ingredients listed and may vary with brands, measurements, and serving sizes.
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