Adapted from The Barefoot Contessa Cookbook
- 1 fennel bulb, trimmed
- 1 small yellow onion, halved and thinly sliced
- 2 leeks, white and green parts only, halved and thinly sliced
- 1 tablespoon olive oil
- 1 tablespoon unsalted butter
- 1 pound russet potatoes (2 large potatoes), peeled and sliced as thin as possible
- 1 cup plus 1 tablespoon heavy cream
- 1 1/4 cup grated Gruyère cheese (1/4 pound)
- 1/2 teaspoon kosher salt
- 1/4 teaspoon freshly ground black pepper
- Preheat the oven to 350°F.
- Butter the inside of an 8 x 8 inch baking dish, or alternatively, 4 oven-proof gratin dishes or soup bowls.
- Cut the fennel bulbs in half lengthwise. Remove the cores and thinly slice the bulbs crosswise, making approximately 4 cups of sliced fennel. Saute the fennel and onions in the olive oil and butter on medium-low heat for 10 minutes, until tender. Add the leeks and sauté for 4 minutes more.
- Mix the potatoes in a large bowl with 1 cup of cream, 1 cup of Gruyère, salt, and pepper. Add the sauteed fennel, onion, and leek mixture and mix well.
- Pour the potatoes into the baking dish. Press down to smooth the potatoes. Combine the remaining cream and Gruyère and sprinkle on the top. Bake for 1 1/2 hours, until the potatoes are very tender and the top is browned and bubbly. Allow to set for 10 minutes and serve.