1 lb. beef liver
1 lg. onion, sliced
4 tbsp. butter
2 tbsp. vinegar
2 tbsp. Worcestershire sauce
2 tsp. sugar
2 tsp. prepared mustard
2 tbsp. water
3/4 c. ketchup

Put all ingredients in a tightly covered baking dish and bake at 375 degrees for 1 hour. Stir halfway through baking.