Name: Cheesy Scalloped Potatoes
Prep time: 25 min
Cook time: 1 h 20 min
Total time: 2 h
Yield: 8 servings
Ingredients: 4 tablespoon unsalted butter; 3 clove garlic (minced); ¼ cup all-purpose flour; 2 cup whole milk; 1 cup heavy cream; 1 ½ teaspoon kosher salt; ½ teaspoon black pepper; 1 teaspoon fresh thyme leaves (or ½ tsp dried); ⅛ teaspoon ground nutmeg; 3 pound Yukon Gold potatoes (peeled and sliced ⅛ inch thick); 1 cup shredded Gruyère cheese (about 4 oz); 1 cup shredded sharp cheddar cheese (about 4 oz); ¼ cup grated Parmesan cheese

Instructions

Make the sauce
Make the sauce:
Preheat the oven to 375°F and butter a 9x13-inch baking dish. Melt 4 tablespoons butter in a saucepan over medium heat, add 3 minced garlic cloves for 30 seconds, then whisk in ¼ cup flour for 1 minute. Slowly whisk in 2 cups milk and 1 cup cream and simmer for 3 to 4 minutes, until thickened. Stir in 1½ teaspoons kosher salt, ½ teaspoon black pepper, 1 teaspoon thyme, and ⅛ teaspoon nutmeg.
Mix the cheeses
Mix the cheeses:
Toss 1 cup Gruyère and 1 cup cheddar together in a bowl.
Layer
Layer:
Arrange one-third of the 3 pounds sliced potatoes in overlapping rows in the dish. Pour one-third of the sauce over them and sprinkle with one-third of the cheese mixture. Repeat twice more, finishing with cheese, then sprinkle ¼ cup Parmesan on top.
Bake
Bake:
Cover with foil and bake for 45 minutes. Uncover and bake for 30 to 35 minutes more, until the potatoes are tender when pierced with a knife and the top is deep golden.
Rest and serve
Rest and serve:
Let the scalloped potatoes rest for 15 minutes so the sauce thickens, then cut into squares and serve.

Tips

Use a mandoline for thin, even potato slices so every layer cooks at the same time. Yukon Golds hold their shape and turn buttery; russets work too but are more crumbly. Don't skip the resting time, or the creamy sauce will run.

Storage

Make ahead: assemble, cover, and refrigerate for up to 1 day, then add 15 minutes to the covered baking time. Leftovers keep in the refrigerator for up to 4 days; reheat covered at 350°F for 20 minutes.