1/2 c. ketchup
1/4 c. vinegar
2 tbsp. chopped onion
1 tbsp. worcestershire sauce
2 tsp. packed brown sugar
1/4 tsp. dry mustard
1 clove garlic, crushed
1 1/2 c. cut up cooked chicken
4 hamburger buns, split

Heat all ingredients except chicken and buns to boiling over medium heat, stirring constantly, reduce heat.

Simmer uncovered, stirring occasionally, for 10 minutes. Stir in chicken. Cover and simmer until chicken is hot, about 5 minutes. Fill hamburger buns with chicken mixture.