Peel sweet potatoes, cut in 1/2 and slice. Cook covered till nearly done in very little boiling water. Take apples (sprinkle with lemon juice, if not tart). Grease baking dish, place alternate layers of sweet potatoes & apples. Sprinkle layers with 1/4 cup brown sugar, cinnamon, dot with butter & pour 1/4 cup water (or apple juice).
Bake 1 hour at 350F.