Wash and peel sweet potatoes. Cut off woody portions and ends. Cut potatoes diagonally into 1/2-inch-thick slices. Place a steamer basket in a saucepan. Add water to just below the bottom of the steamer basket. Bring to boiling. Add potato slices. Cover and reduce heat. Steam for 10 to 15 minutes or until just tender; cool.
Meanwhile, core the unpeeled apple and cut into 12 wedges. In a greased, two-quart casserole combine potato slices and apple wedges.
In a small saucepan bring the brown sugar, water, margrine or butter, and cloves to boiling. Drizzle the mixture evenly over potatoes and apples.
Bake, uncovered, in a 350 degree F oven for 30 to 35 minutes or until potatoes and apples are glazed, stirring twice. Sprinkle potatoes and apples with toasted pecans or walnuts. Makes 4 servings.