Ham Barbecue Sauce - cooking recipe

Ingredients

2 medium onions, diced
2/3 c. ketchup
2 Tbsp. vinegar
2 Tbsp. butter
2 Tbsp. sugar
2 Tbsp. mustard

Preparation

Saute onions in butter until soft.
Add all remaining ingredients and cook on medium fire for 10 minutes.
Let cool and add 1 pound cold ham, sliced thin.
Serve on hamburger buns.