It’s hard to go wrong with potatoes. In fact, it’s practically impossible. You’ll also be hard-pressed to mess up something with melted cheese. And this, friends, is why potato au gratin is a dish you have to keep on hand.
Ingredients:
- 4 medium russet potatoes, thinly sliced
- 1 medium onion, sliced into rings
- 3 tablespoons butter
- 3 tablespoons all-purpose flour
- 2 cups milk
- 1 cup cheddar cheese, shredded
- 1 cup Gruyère cheese, shredded
- Chopped thyme
- ½ teaspoon salt
- Ground black pepper
Instructions:
- Preheat the oven to 400°F and butter a casserole dish.
- Layer half of the potatoes in the bottom of the casserole dish and season with salt and pepper. Layer onion slices on top, then top with the remaining potatoes. Season again with salt and pepper.
- Melt butter in a medium saucepan over medium heat. Gradually whisk in flour and salt and cook, whisking constantly, for 1 minute, until the raw flour flavor has cooked off.
- Gradually add milk, about 1/4 cup at a time, whisking well after each addition.
- Once the mixture has thickened, stir in the cheese and continue stirring until melted. Pour the cheese sauce over the potatoes, top with thyme, and cover the dish with aluminum foil.
- Bake in the oven for 1.5 hours until the potatoes are tender and the sauce is bubbly.
