Balsamic Barbeque Chicken

6 boneless skinless chicken breasts (or equivalent)

1/2 cup chopped onion
3/4 cup Balsamic Vinaigrette dressing
3-4 Tablespoons sugar*
1/3 cup ketchup

Mix ingredients together.  Reserve 3/4 cup and refrigerate.  Pour remaining sauce over chicken and marinate 4-24 hours.(The longer you marinate, the better flavor you get.)  Remove chicken from marinade and bake, broil or grill it. When chicken is cooked thoroughly, heat up reserved sauce and pour over top of chicken.
Serves: 6

*Add the sugar according to your tastes.  I have noticed that some Balsamic Vinaigrettes are more sweet than others so you don't need as much.

Recipe Source - Once Crazy Cookie