1/4 c. fat or salad oil
1 lb. ground beef
1 c. catsup
2 tsp. cider vinegar
1/2 c. chopped onions
1 tsp. salt
2 tbsp. prepared mustard
1 lb. pinto beans, cooked

Heat fat in skillet. Add onions and saute until transparent. Add ground beef; stir until browned. Add remaining ingredients. Pour into 2 quart casserole and bake in 400 degree oven for 30 minutes.