Pommes Duchesse Gratin

Preparation Put oven rack in middle position and preheat oven to 400°F. Prick each potato a few times, then bake in a shallow baking pan until tender, about 1 hour. When potatoes are just cool enough to handle, halve and scoop out flesh. Force flesh through ricer or food mill into a bowl. Heat cream with butter and garlic in a 3-quart heavy saucepan over moderately low heat until hot, then stir into potatoes. Beat in eggs 1 at a time with a fork until blended, then stir in salt, white pepper, and nutmeg. Spoon mixture into a buttered 2-quart (10-inch) round or oval shallow gratin or casserole dish. Bake until top is puffed and golden, 30 to 40 minutes. Cooks' notes:·Gratin can be prepared (but not baked) 1 day ahead and cooled completely, uncovered, then chilled, its surface covered with buttered wax paper and dish wrapped in plastic wrap. Bring to room temperature, about 1 hour, before baking. ·If you have only one oven, bake gratin while rib roast stands.

Preparation Put oven rack in middle position and preheat oven to 400°F. Prick each potato a few times, then bake in a shallow baking pan until tender, about 1 hour. When potatoes are just cool enough to handle, halve and scoop out flesh. Force flesh through ricer or food mill into a bowl. Heat cream with butter and garlic in a 3-quart heavy saucepan over moderately low heat until hot, then stir into potatoes. Beat in eggs 1 at a time with a fork until blended, then stir in salt, white pepper, and nutmeg. Spoon mixture into a buttered 2-quart (10-inch) round or oval shallow gratin or casserole dish. Bake until top is puffed and golden, 30 to 40 minutes. Cooks' notes:·Gratin can be prepared (but not baked) 1 day ahead and cooled completely, uncovered, then chilled, its surface covered with buttered wax paper and dish wrapped in plastic wrap. Bring to room temperature, about 1 hour, before baking. ·If you have only one oven, bake gratin while rib roast stands.