Cut the steak into finger-shaped pieces. Cut the kidney into thin slices and season well. Fry the steak for a few minutes in the dripping to seal the surface. Mix the flour, eggs and milk or water into a smooth batter and season. Melt about ½ oz. dripping in a casserole or pie-dish and put in half the batter and bake until set. Place the steak and the kidney on top of the batter, fill up the dish with the remainder of the batter and bake in a hot oven (425° F., Gas 7) for 10 min.; then reduce to moderate (350° F., Gas 4) for about 1 hr. until set and well browned. Serve with a good gravy.