Combine crumbs, cheese, egg, milk, onion, monosodium glutamate, salt and pepper with ground steak; shape into balls.
Place meatballs in shallow greased baking pan.
Bake at 350 degrees until browned.
Remove meatballs from pan.
Blend flour into pan drippings; add bouillon and mushrooms.
Stir until smooth and blended; add meatballs to sauce.
Bake, covered, at 350 degrees for 30 minutes.
Serve over rice.