Potato and Leek Gratin
- SERVINGS: 8
For the final baking, be sure to use a rimmed baking sheet. If you're planning to serve the gratin with roasted lamb, put it in the oven for the final baking while the loins roast, but begin checking for browning after 15 minutes.
- 3 pounds waxy potatoes, such as Yukon Gold, peeled and thinly sliced
- 1 pound leeks, white part only, thinly sliced
- 2/3 cup olive oil
- Salt and freshly ground pepper
- Preheat the oven to 350°. In a medium bowl, gently toss the potatoes with the leeks, olive oil, 1 1/2 teaspoons salt and 1/2 teaspoon pepper. Transfer the potatoes to a 9-by-13-inch glass or ceramic baking dish and pat into an even layer. Cover the potatoes with foil and bake for about 1 1/2 hours, or until the potatoes are tender. Let cool completely, then cover with plastic wrap and refrigerate until chilled.
- Preheat the oven to 450°. Cut the gratin into 8 squares. using a metal spatula, transfer the squares to a rimmed nonstick baking sheet. Bake for 30 minutes, or until the tops are brown. Serve immediately.
Make Ahead The potatoes can be refrigerated overnight.