2 to 3lbswhite turnipspeeled and sliced 1/4 inch thick
2 to 3lbssweet potatoespeeled and sliced 1/4 inch thick
1/4lbunsalted butter
1 to 2tbspfinely chopped fresh tarragon leaves
Salt
Freshly ground black pepper
1cupgrated imported Parmesan cheese
1cupbread crumbs
2cupsheavy cream
Instructions
Preheat the oven to 350°F. Butter a 3-quart casserole.
To blanch the turnips, bring a large pot of water to the boil. Add the sliced turnips and cook 5 minutes. Remove them and drain thoroughly in a strainer.
Gently combine the turnips and sweet potatoes. Place a layer of the vegetables in the casserole and dot with half the butter. Sprinkle generously with tarragon, salt, and pepper, and cover with half the Parmesan. Make another layer.
Top with the bread crumbs and pour the cream around the sides. Dot with the remaining butter and Parmesan.
Bake until the vegetables are soft but not mushy, 1 to 1-1/2 hours.