Fennel and Potato Bake

3 Tbls butter
2 fennel bulbs, halved, cored and sliced very thin
1 ½ lbs. potatoes, peeled and sliced very thin
Salt and pepper
¾ cup grated parmesan cheese
½ cup heavy cream

Preheat oven to 400. Butter an 8-inch square baking dish. Add potatoes in 3 layers, alternating with 2 layers of fennel. Season each potato layer with salt and pepper, dot with 1 Tbls butter, and sprinkle with 2 Tbls cheese. Pour cream over top and bake until potatoes are tender, about 45 min. Sprinkle with remaining ½ cup cheese and bake until golden-brown, 15-20 min.