Fennel, Leek and Potato Gratin

Serves 6–8

The traditional French potato gratin features potatoes, cream and cheese baked to perfection. Those classic ingredients have been adapted over the years for endless variations, such as our fennel, leek and potato version. Fennel is a wonderful addition: Its subtle anise flavors melt together with Gruyere’s nuttiness, and its texture adds interest to every bite.

3 fennel bulbs

2 leeks, white and light green parts, sliced and rinsed

1 pound russet potatoes, peeled

2 tablespoons extra-virgin olive oil

2 tablespoons unsalted butter, plus more for buttering the pan

2 cups heavy cream

2 garlic cloves, minced

2 tablespoons Dijon mustard

2½ cups shredded Gruyere cheese, divided

1½ teaspoons kosher salt

½ teaspoon ground black pepper

Preheat oven to 350°. Butter a 9- by 13-inch baking dish and set aside. Cut the top fronds and stems from the fennel bulbs, cutting as close to the bulb as possible. Set aside the fronds for garnish. Cut the fennel bulbs in half from top to bottom and cut out the tough core from each half. Using a mandoline or knife, slice the halves as thinly as possible.

Heat the olive oil and butter in a large skillet over medium-low heat. Sauté the fennel and leeks together until just tender, 8 to 10 minutes. Meanwhile, thinly slice the potatoes. In a large bowl, stir together the heavy cream, garlic, Dijon mustard, 2 cups of cheese, salt and pepper. Add the fennel/leek mixture and sliced potatoes and toss until everything is evenly coated.

Pour the mixture into the prepared pan. Bake for 45 minutes. Remove from the oven andsprinkle the remaining ½ cup cheese on top. Return to the oven and bake for another 15 to 30 minutes, until the potatoes are tender and the top is browned and bubbling. Garnish with fennel fronds and allow to cool for 10 minutes before serving.