Pound chicken to a half inch in thickness then place in a gallon-sized resealable bag.
In a small bowl, whisk together all remaining ingredients then pour over chicken, seal bag and let marinate in the refrigerator for at least 4 hours, preferably overnight.
Preheat grill to medium heat. Remove chicken from the bag, discarding marinade, and grill for 5-7 minutes on each side or until it reaches an internal temperature of 165 degrees F.