Adapted from The Barefoot Contessa Recipe found Here
~from Savoring Time in the Kitchen
My adapted recipe serves 4
1 fennel bulb
1/2 very large onion, thinly sliced (like Vidalia or other sweet onion)
1 tablespoons good olive oil
1/2 tablespoon unsalted butter
1 pound russet potatoes
1 cup plus 2 tablespoons heavy cream (I substituted 1/2 cup of fat free half and half)
1-1/2 cups grated Gruyère or good Swiss cheese
1 teaspoon kosher salt
1/2 teaspoon freshly ground black pepper
Preheat the oven to 350 degrees F.
Remove the fennel stalks and cut the bulbs in half lengthwise. Remove the core and thinly slice the bulb crosswise. You should have approximately 2 cups of sliced fennel. Saute the fennel and onions in the olive oil and butter on medium heat for 15 minutes, until tender and slightly browned.
Peel the potatoes and slice. (Using a mandoline makes quick work of this step.) Mix the sliced potatoes in a large bowl with 1 cup of cream, 1 cup of Gruyère, salt and pepper. Add the sauteed fennel and onion and mix well. (I did all of the mixing in the pan I used to saute the onions and fennel).
If not using a large saute pan as I did, pour the potatoes into the prepared baking dish. Press down to smooth the potatoes. Combine the remaining 2 tablespoons of cream and 1/2 cup of 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.