Scalloped Potatoes 101

3 cups whole milk
1¼ teaspoons salt
½ teaspoon freshly ground black pepper
8 medium (4 pounds) baking potatoes, such as russet, peeled and sliced into 1/8-to ¼-inch-thick rounds
4 tablespoons unsalted butter, cut into small pieces
1½ cups (12 ounces) shredded extra-sharp cheddar cheese
3 tablespoons minced onion
3 tablespoons all-purpose flour

Good old-fashioned scalloped potatoes, layered with milk and sharp cheddar cheese, have a special place in the hearts of American cooks.

Position a rack in the center of the oven and preheat to 400°F. Lightly butter a 13 × 9-inch glass baking dish.
In a medium saucepan over medium-high heat, heat the milk until small bubbles appear around the edges. In a small bowl, mix the salt and pepper together.
Layer half of the potatoes over the prepared dish. Season with half the salt-and-pepper mixture and dot with 2 tablespoons of the butter. Sprinkle with 1 cup of the cheese, the onions, and the flour. Spread the remaining potatoes on top. Season with the remaining salt-andpepper mixture and dot with the remaining 2 tablespoons butter. Pour the hot milk over all. Cover tightly with aluminum foil. Place the dish on a baking sheet.
Bake for 45 minutes. Uncover and sprinkle with the remaining ½ cup cheese. Continue baking, uncovered, until the potatoes are tender, about 45 minutes. (The scalloped potatoes can be made 2 hours ahead of serving. Let stand at room temperature. Cover loosely with aluminum foil and reheat in a preheated 350°F oven until heated through, about 20 minutes. Or cover with plastic wrap and reheat in a microwave on Medium for about 10 minutes.) Let stand for 10 minutes before serving. Serve hot.