Ingredients
- 3 lbs yellow potatoes, peeled and sliced paper thin
- 1 clove garlic
- 3 cups milk
- 5 oz Gruyère cheese, grated
- 3 T unsalted butter, room temperature
- Salt and freshly ground black pepper
- 1 cup heavy cream
Directions
- Rub a 3½-quart oval casserole dish with garlic and butter.
- In a large saucepan, combine sliced potatoes and milk. Place over high heat. Bring to boil, then reduce to simmer until potatoes just begin to get tender, about 3 minutes.
- Meanwhile, grate cheese. Drain potatoes, reserving milk (you should have about 2 cups — add milk if needed).
- Arrange sliced potatoes in the casserole in two layers with salt and pepper.
- Pour in the reserved cooking milk and cream. Scatter grated Gruyère over the top.
- Bake in the lower third of the oven at 325°F until the cheese has turned deep golden brown and the milk has reduced and thickened, 80–90 minutes.
- Remove from oven and serve immediately.
Note: Slice the potatoes as thin as possible — a mandoline is ideal. The paper-thin slices cook evenly and absorb the cream beautifully.