Ingredients

5 tablespoons unsalted butter, softened
8 medium russet potatoes, peeled and sliced 1/8-inch-thick
1 large yellow onion, thinly sliced
1 cup heavy cream
2 teaspoons kosher salt
1/2 to 1 teaspoon freshly ground black pepper, to taste
1/4 teaspoon ground nutmeg
1/2 cup grated hard cheese, such as Parmesan, Dry Jack or pecorino Romano
2 tablespoons chopped fresh herbs, such as thyme, parsley and/or chives

Directions

Preheat the oven to 350 F. Grease a 12-by-9-inch ceramic or glass baking dish with 1 tablespoon of the butter.

Toss together the potatoes, onion, cream, salt, pepper and nutmeg in a large bowl. Line the bottom of the baking dish with an even layer of potatoes and onion. Dot the surface with 1 tablespoon of the remaining butter. Repeat layering until the dish is full, and pour any remaining cream over the top. Press down on the potatoes so that they are an even thickness. Dot the surface with any remaining butter and sprinkle with the cheese.

Bake uncovered until the potatoes are tender, the cream is absorbed, and the cheese is golden and crisp, about 1 hour. Sprinkle the herbs on top of the dish just before serving. Makes 8 servings.