Gratin Dauphinois

Serves 8
 2 ½ lbs boiling potatoes, such as yukon gold
3 ½ cups half-and-half
2 large garlic cloves, minced
1 tsp salt ¼ teaspoon freshly grated nutmeg
¾ cup coarsely grated gruyere

Put a rack in the middle of oven and preheat oven to 400 degrees F. Generously butter a 2 ½- to 3-quart gratin dish or other shallow baking dish. Peel potatoes. Cut crosswise into 1/16-inch-thick slices with slicer and transfer to a 4-quart heavy saucepan. Add half-and-half, garlic, salt, and pepper and bring just to a boil over moderate heat. Pour potato mixture into buttered dish, distributing potatoes evenly. Sprinkle nutmeg and cheese evenly over top. Bake until potatoes are tender and top is golden brown, 35 to 45 minutes. Let stand for 15 minutes before serving. The gratin can be made up to 1 day ahead. Cool completely, then refrigerate, covered. Bring to room temperature before reheating, covered, in a 350 degree oven.