Barbecued Chicken with Vinegar Basting Sauce

Ingredients:
- 1 1/4 cups cider vinegar
- 4 teaspoons chili powder
- 2 1/2 teaspoons salt
- 1 1/2 teaspoons sugar
- 1 teaspoon cayenne pepper
- 1 teaspoon dry mustard
- 1 teaspoon paprika
- 1 teaspoon ground black pepper
- 1/2 teaspoon ground cumin
- 4 skinless boneless chicken breast halves

Directions:
- Prepare barbecue (medium-high heat) or preheat broiler.
- Whisk first 9 ingredients in small bowl to blend.
- Arrange chicken in shallow glass dish.
- Spoon 1/4 cup sauce over; turn to coat evenly.
- Let stand at least 10 minutes and up to 30 minutes, turning chicken occasionally.
- Grill chicken until just cooked through, basting occasionally with another 1/4 cup sauce, about 5 minutes per side.
- Serve with remaining sauce.