Make small beef patties and set aside. Peel potatoes and slice thinly. Peel onions and slice thinly. Melt butter in frying pan. Place onions in butter and lightly cook, just until transparent. Remove and place beef patties in butter. Brown quickly. Do not cook done. Place the potatoes in bottom of casserole dish with beef patties and onions on top. Pour water into pan in which onions were cooked and then pour over potatoes. Bake at 200ºC or 45 minutes.