Apple Yams

Peel, cook and slice   2 large yams.  Put in buttered casserole dish.  Peel and slice 4 medium apples.  Arrange in casserole dish on top of yams.  Sprinkle cinnamon on the apples.  Combine 2 c. water, 1 c. sugar, 1 cube margarine, 3 T cornstarch, ¼ t. salt, 1 T lemon juice and bring to a boil.  Pour over apple/yam mixture.  Bake uncovered at 325 until apples are tender.