Place potatoes in a small saucepan covered with cold water and a pinch of salt. Bring to a boil over high heat, and cook for 1 1/2 minutes. Remove from heat and drain.

Heat heavy cream in a medium saucepan with garlic over medium-low heat until reduced to 2 cups, about 30 minutes. Add drained potatoes, salt, pepper, and nutmeg. Cook over medium heat, stirring occasionally, until potatoes are tender, about 15 minutes.

Remove garlic and divide cooked potatoes between two 6-inch round gratin dishes or one large gratin dish. Sprinkle with cheese, and place under broiler until golden.

Serves 4.