Trim excess fat from ham; cut into 4 equal portions. Cut up any large sweet potatoes. Arrange sweet potatoes and apple wedges in a 2 quart rectangular baking dish. Arrange ham pieces atop sweet potatoes and apples.
In a saucepan combine orange peel, orange juice, cornstarch, soy sauce, ginger, and garlic. Cook and stir until thickened and bubbly. Pour over ingredients in baking dish.
Bake, covered, in a 375 degree F oven for 15 minutes. Uncover and bake about 10 minutes more until apples are just tender. Makes 4 servings.