Ingredient	Amount
Garlic	1 clove, lightly smashed and peeled
Unsalted butter	Room temperature, for pan
Yukon Gold potatoes	4 pounds (8 medium)
Heavy cream	2 cups
Whole milk	2 cups
Fresh thyme leaves	1 tablespoon, lightly packed
Coarse salt	To taste
Freshly ground pepper	To taste
Freshly grated nutmeg	1/8 teaspoon
Gruyere	6 ounces, coarsely grated (2 1/4 cups)

Instructions

Preheat oven to 375 degrees. Rub the bottom and sides of a 3-quart baking dish with garlic; reserve garlic. Brush pan generously with butter. Peel potatoes, then cut into 1/8-inch-thick rounds.

Transfer potatoes and garlic to a large pot with cream, milk, thyme, 1 tablespoon salt, 1/2 teaspoon pepper, and nutmeg. Bring to a boil over high. Reduce heat to medium and simmer 1 minute. Let cool slightly, about 10 minutes.

Spoon one-third of potato mixture into prepared dish. Sprinkle with one-third of cheese. Repeat layering twice more. Loosely cover dish with parchment-lined foil.

Bake until potatoes are tender when pierced with the tip of a knife, 35 to 40 minutes. Remove foil; turn oven to broil. Broil until potatoes are bubbly and browned in places, 3 to 5 minutes. Let cool 15 minutes before serving.

Source: Martha Stewart