Description

This creamy and cheesy au gratin potatoes recipe features thinly sliced Yukon Gold potatoes layered with a rich cheddar cheese sauce, baked to golden perfection with Gruyere and Parmesan toppings. It makes a comforting side dish perfect for family dinners or holiday meals, delivering a luscious combination of tender potatoes and savory cheese flavors.

Ingredients

Scale

Potatoes & Vegetables

6–7 medium Yukon Gold potatoes (3 lbs), thinly sliced into 1/8-inch rounds
½ white or yellow onion, sliced

Cheese Sauce

2 tablespoons salted butter
¼ cup all-purpose flour (or gluten-free 1:1 flour)
1½ cups unsweetened almond milk (or regular/whole milk)
8 ounces sharp cheddar cheese (about 2 heaping cups, shredded)
½ teaspoon garlic powder
¾ teaspoon salt (plus more to taste)
Freshly ground black pepper, to taste

Toppings & Garnish

½ cup Gruyere cheese (or substitute with more sharp cheddar)
¼ cup grated Parmesan cheese
Fresh chopped parsley

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Instructions

Preheat the Oven: Preheat your oven to 375°F (190°C) and prepare your baking dish by greasing a 2-quart square baking dish or an 8×12-inch pan with nonstick spray, butter, or oil to prevent sticking.
Layer the Potatoes & Onions: Arrange the thinly sliced potatoes in three slightly slanted rows inside the dish, making sure to leave small gaps between slices for even cooking. Distribute the sliced onions between and on top of the potato layers to add flavor.
Prepare the Cheese Sauce: In a medium saucepan over medium heat, melt the butter. Gradually whisk in the flour, alternating with the almond milk, to form a smooth, lump-free mixture. Bring it to a simmer, whisking constantly until the sauce thickens to a gravy-like consistency. Reduce the heat to low, then stir in the shredded sharp cheddar cheese, garlic powder, salt, and freshly ground pepper. Taste and adjust seasoning as needed.
Assemble the Dish: Pour the prepared cheese sauce evenly over the potato and onion layers, ensuring every slice is well coated for rich flavor throughout the dish.
Bake Covered: Cover the baking dish tightly with aluminum foil and place it in the preheated oven. Bake for 45 minutes to allow the potatoes to begin softening and the flavors to meld.
Add Toppings & Finish Baking: Carefully remove the foil and sprinkle the Gruyere (or additional cheddar) and Parmesan cheeses evenly over the top of the potatoes. Return the dish to the oven and bake uncovered for an additional 30 to 45 minutes. The dish is done when the potatoes are fork-tender and the cheese topping is beautifully golden brown.
Garnish & Serve: Remove the dish from the oven and garnish with freshly chopped parsley for a fresh finish. Serve the au gratin potatoes hot as a delicious, cheesy side dish.

Notes

Use Yukon Gold potatoes for creamy texture and even cooking, but russets can also be used.
For a gluten-free version, substitute all-purpose flour with a 1:1 gluten-free flour blend.
Unsweetened almond milk offers a dairy-free twist, but whole milk will deliver creamier results.
If Gruyere cheese is unavailable, additional sharp cheddar can be used as a substitute.
Allow the dish to rest for 5 minutes after baking to set for easier serving.