1 lb. ground beef
1 sm. onion, chopped
1/2 c. catsup
1 tsp. dry mustard
1 tsp. brown sugar
1 tsp. vinegar
1 tsp. flour
Salt and pepper to taste

Brown ground beef and onion. Add remaining ingredients and stir. Allow to simmer 15-20 minutes, stirring often. Serve on hamburger buns.