This Potatoes Au Gratin recipe delivers layers of thinly sliced Russet potatoes baked in a rich, creamy cheese sauce with butter, milk, and garlic. Perfectly golden and bubbly on top, this classic side dish is a favorite for holiday dinners, family gatherings, and comfort food meals. Made with cheddar or Gruyère cheese, it pairs beautifully with roast beef, chicken, ham, or turkey. Easy to prepare and impressive on the table, this homemade gratin potatoes recipe offers a warm, hearty texture that makes it one of the best cheesy potato casserole dishes for any occasion.

This classic Potatoes Au Gratin recipe features thinly sliced potatoes layered in a rich, creamy cheese sauce made from scratch. With a golden, bubbly top and a perfectly tender interior, it’s a comforting side dish that pairs beautifully with any main course — from roasted meats to holiday feasts.

Ingredients

6 medium Russet potatoes
6 tablespoons butter
6 tablespoons all-purpose flour
2 cups milk
1 cup heavy whipping cream
1 teaspoon salt
2 cloves garlic, minced
1½ teaspoons dried onion flakes
Salt and freshly ground black pepper, to taste
3 cups freshly grated sharp cheddar cheese or Gruyère (or a mix of both)

Instructions

Prepare the Cheese Sauce
In a medium saucepan over medium heat, melt the butter. Whisk in the flour and cook for 1–2 minutes, stirring constantly, until smooth and lightly golden.
Gradually add the milk and cream while whisking to prevent lumps. Stir in the minced garlic, dried onion flakes, salt, and pepper. Continue cooking over low heat until the sauce slightly thickens.
Reduce the heat and stir in 2 cups of shredded cheese until fully melted and smooth. Taste and adjust seasoning if needed.
Prepare the Potatoes
Peel the potatoes if desired. Slice them into thin, even slices (about ⅛ inch thick) using a sharp knife or mandoline slicer.
Assemble the Dish
Lightly grease a 9×13-inch casserole dish. Spread half of the sliced potatoes evenly in the dish. Pour half of the cheese sauce over them, spreading to coat.
Add the remaining potatoes on top and spoon the rest of the cheese sauce evenly over the surface. Sprinkle the remaining 1 cup of shredded cheese on top.
Bake
Cover the dish with aluminum foil and bake in a preheated oven at 350°F (175°C) for 30 minutes.
Remove the foil and bake uncovered for another 30 minutes, or until the potatoes are tender, the top is golden brown, and the sauce is bubbling.
Cool and Serve
Allow the gratin to rest for 10 minutes before serving to let the sauce thicken slightly.

Tips

Slice the potatoes thinly and evenly for even cooking.
Use freshly grated cheese — pre-shredded cheese contains anti-caking agents that affect melting.
Let the dish rest before serving to achieve the perfect creamy consistency.
Add a pinch of nutmeg or smoked paprika for extra depth of flavor.

Variations and Substitutions

Cheese: Try Gruyère, Swiss, or Monterey Jack for different flavors.
Add-ins: Include caramelized onions, crispy bacon, or sautéed mushrooms for extra richness.
Dairy-free: Substitute with plant-based milk, vegan butter, and dairy-free cheese.
Potatoes: Yukon Golds work well for a creamier texture.

FAQs

Can I make this ahead of time?
Yes. Assemble the dish, cover tightly, and refrigerate for up to 24 hours. Bake just before serving.

Can I freeze Potatoes Au Gratin?
Yes. Cool completely, wrap well, and freeze for up to 2 months. Reheat covered at 350°F until hot and bubbly.

Why are my potatoes still firm after baking?
They may have been sliced too thick or not baked long enough. Continue baking until tender when pierced with a fork.

Can I use half-and-half instead of cream?
Yes, but the sauce will be slightly lighter in texture.

Serving Suggestions

Serve Potatoes Au Gratin with roasted chicken, beef, ham, or turkey. It’s also an excellent side for steak dinners, holiday meals, or Sunday roasts. Add a green salad or steamed vegetables to balance the richness.

Why You’ll Love This Recipe

Rich, creamy, and cheesy with perfectly tender potatoes.
Ideal for holidays, family dinners, or special occasions.
Simple ingredients, easy method, and crowd-pleasing flavor.
Elegant presentation that elevates any meal.