- 1 pound large red potatoes
- 3/4 cup coarsely grated Gruyère (about 3 ounces)
- 1 large egg
- 1 cup milk, heated just to boiling
- Preheat oven to 400°F. and butter a 1 1/2-quart gratin or shallow baking dish.
- Bring a large saucepan of salted water to a boil. Peel potatoes and cut into thin slices (about 1/8-inch thick). Add potatoes to boiling water and parcook 4 minutes. Drain potatoes well in a colander.
- In gratin or baking dish arrange potatoes, overlapping them, in 3 layers, sprinkling first two layers each with 1/4 cup Gruyère and salt and pepper to taste.
- In a small bowl whisk egg and add hot milk in a stream, whisking. Season mixture with salt and pepper and pour evenly over potatoes. Sprinkle potatoes with remaining 1/4 cup cheese and bake 30 minutes, or until top is golden and potatoes are tender.