Preheat oven to 350 deg F. In skillet, saute onion and celery in margarine 2 minutes. Add beef and salt and stir another 2 minutes. Spread half the cabbage in 2 qt baking dish and cover with half the apples and all the meat mixture. Add remaining cabbage and apple slices. Cover and bake 1 hour. Good with mashed potatoes or noodles. Serves 6.