Potato and Leek Gratin

I stumbled upon this recipe on the Williams Sonoma website over the holidays while trying to find a new potato recipe for our holiday feast. I ended up making a few adjustments to it, but overall kept the integrity of the original. The simple combination of leeks and potatoes is classic and with the addition Gruyère, Parmigiano-Reggiano, and nutmeg this gratin is quite indulgent! My major shortcut was using frozen leeks which saved a great deal of time not having to clean the leeks as they usually require special attention in that department. We absolutely loved this gratin and will most certainly be making it again in the future. I always enjoy dishes that you can stick in the oven and forget about for a while, and this is one of them. Allow yourself enough time, as it takes 1 ½ hours from start to finish, but the prep time is minimal.

Potato and Leek Gratin
adapted from Williams Sonoma

serves 4-6

Ingredients:

2 tablespoons unsalted butter
2 cups of leeks, white and light green portions, rinsed well, cut into 1/4-inch rings
3/4 tablespoon kosher salt
1 teaspoon minced fresh thyme
1/8 teaspoon freshly grated nutmeg
½ teaspoon ground pepper
1/2 cup heavy cream
3 oz. Gruyère cheese, grated
1 1/2 oz. Parmigiano-Reggiano cheese, grated
3 medium sized Yukon gold potatoes, cut into 1/4-inch slices

Directions:
Preheat an oven to 400ºF.

In a 12-inch nonstick fry pan over medium heat, melt the butter. Add the leeks and salt, stirring to coat the leeks with the butter. Saute for 5-10 minutes or until leeks are soft and translucent. Add the thyme, nutmeg, pepper and cream and simmer, uncovered, stirring occasionally, until thickened, about 5 minutes.

Prepare a baking dish by spraying it with cooking spray.

In a bowl, combine the Gruyère and Parmigiano-Reggiano cheeses. Layer one-half of the potatoes in the baking dish and spread one-half of the leek mixture on top. Sprinkle with one-half of the cheeses. Repeat the layering one more time.

Cover the dish, transfer to the oven and bake for 45 minutes. Remove the lid and continue baking until the potatoes are tender and the crust is golden brown, about 15-30 minutes more. Let the gratin stand for 15 minutes before serving.