Tavern burgers

Ingredients:

1 1/2 C. chopped onion
3 T. butter
1 can tomato soup
1/2 C. water
1/4 C. vinegar
2 T. prepared mustard
2 T. Worcestershire sauce
2 T. brown sugar
2 lb. ground beef
Salt and pepper, to taste

Preparation:

Combine and cook 1 cup onion and butter until clear and tender.
Remove from fire and add remaining ingredients except beef, salt and pepper. Simmer for 10 minutes.
Cook ground beef and remaining onion until brown. Add to mixture.
Salt and pepper to season. Spread on toasted buns.