Description

Dad’s Creamy & Cheesy Au Gratin Potatoes are a rich and comforting side dish featuring tender thinly sliced russet potatoes baked in a velvety cheese sauce made from sharp cheddar, Gruyère, and Parmesan. Perfect for holidays and family dinners, this recipe layers potatoes with a homemade creamy cheese sauce, baked to golden perfection, offering a warm, indulgent treat that will please any crowd.

Ingredients

Scale

Potatoes

4 large russet potatoes, peeled and thinly sliced

Sauce

3 tablespoons unsalted butter
3 tablespoons all-purpose flour
2 cups whole milk
1 cup heavy cream
2 cups sharp cheddar cheese, shredded
1 cup Gruyère cheese, shredded
1 small onion, finely chopped
2 cloves garlic, minced
1 teaspoon salt
½ teaspoon black pepper
¼ teaspoon ground nutmeg

Topping & Garnish

½ cup grated Parmesan cheese
2 tablespoons fresh parsley, chopped (optional, for garnish)

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Instructions

Preheat and Prepare Dish: Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish with butter or nonstick spray to prevent sticking and ensure even cooking.
Slice Potatoes: Peel and slice the russet potatoes into thin, uniform rounds about 1/8 inch thick. Place them in cold water to prevent browning while you prepare the sauce.
Cook Onion and Garlic: In a large saucepan over medium heat, melt the butter. Add the finely chopped onion and cook until softened, about 3-4 minutes. Stir in the minced garlic and cook for an additional 30 seconds until fragrant.
Make Roux: Sprinkle the flour over the butter, onion, and garlic mixture. Stir constantly to combine and cook for 1-2 minutes to remove the raw flour taste, forming a roux which will thicken the sauce.
Add Milk and Cream: Gradually whisk in the whole milk and heavy cream, continuing to whisk to keep the sauce smooth. Cook for about 5 minutes until the sauce thickens slightly.
Melt Cheese and Season: Reduce heat to low. Add sharp cheddar and Gruyère cheeses to the sauce, stirring until melted and smooth. Season with salt, black pepper, and ground nutmeg for warmth and balance.
Layer Potatoes and Sauce: Drain the sliced potatoes well and pat dry with a towel. Arrange a layer of potato slices evenly in the baking dish. Pour a portion of the cheese sauce over the potatoes, spreading it evenly. Repeat layers with remaining potatoes and cheese sauce, ensuring the final top layer is covered with sauce.
Add Topping: Sprinkle grated Parmesan cheese evenly over the top of the layered potatoes and sauce. Cover the dish tightly with foil to prevent the top from burning during the initial baking phase.
Bake: Bake in the preheated oven for 45 minutes covered. Then remove the foil and continue baking for an additional 20-25 minutes until the top is golden brown, bubbly, and the potatoes are tender when pierced with a fork.
Rest and Garnish: Allow the dish to rest for 10 minutes out of the oven to set before serving. Optionally sprinkle with chopped fresh parsley for a fresh burst of color and flavor.

Notes

For a lighter version, substitute half-and-half for heavy cream and use reduced-fat cheeses.
Add cooked bacon bits or caramelized onions between layers for extra flavor and texture.
Using a mandoline slicer helps achieve uniformly thin potato slices, ensuring even cooking.