Au Gratin Turnips and Potatoes

4 cups turnips & potatoes (any combination,) peeled and thinly sliced
1 medium Onion peeled and finely sliced
2 tb Melted butter
1/2 c Milk
1/8 ts Grated nutmeg
1/4 ts Ground pepper
1/2 ts Salt
1/2 cup Grated cheese

Instructions:
Preheat the oven to 375 degrees. Mix the turnips, potatoes, onion and melted melted butter together and place in a 9-inch square or round baking dish. Cover tightly and place in preheated oven for 30 minutes. In a small pot on top of the stove combine milk, nutmeg, pepper and salt and bring to a boil. Immediately remove from heat. Remove turnip-potato mixture from the oven, remove the cover from the baking dish and mix in half the cheese. Pour the milk over the potatoes and sprinkle with remaining cheese. Replace in oven, uncovered, another 20 to 25 minutes. When the gratin is golden brown, it's ready to serve. You can also put it under the broiler for a few minutes if you feel that the vegetables are soft enough but the gratin is not brown enough.