Scalloped potatoes are a creamy, rich, and cheesy side dish perfect for any meal. Baked to perfection with a luscious sauce, these potatoes are a comfort food classic!
Preheat oven to 375°F (190°C) and grease a baking dish.
Thinly slice potatoes (about 1/8-inch thick) using a mandoline slicer or sharp knife. Soak in cold water for 10 minutes, then drain and pat dry.
Melt butter in a saucepan over medium heat. Add onions and garlic, cooking until fragrant.
Stir in flour and cook for 1 minute. Gradually whisk in milk and heavy cream, stirring constantly. Simmer for 3-5 minutes until thickened. Season with salt, pepper, and nutmeg.
Arrange half of the sliced potatoes in the baking dish. Pour half of the creamy sauce over them. Repeat with another layer of potatoes and sauce.
If making a cheesy version, sprinkle cheddar between layers and Parmesan on top.
Cover with foil and bake for 45 minutes. Remove foil and bake for another 25-30 minutes until golden brown and bubbly.
Let the dish rest for 10 minutes before serving. For a crispy top, broil for 2-3 minutes before serving.
Notes
For extra flavor, add ham, bacon, or herbs like rosemary or thyme. Make ahead and refrigerate for up to 24 hours before baking.