In a small bowl, whisk chicken rub ingredients together and rub evenly all over chicken breasts. Time permitting, allow chicken to sit for 30 minutes at room temperature or refrigerate up to 8 hours then bring to room temperature before cooking.*If chicken has been refrigerated, let sit at room temperature for 15-30 minutes (time permitting).
Meanwhile, grease and preheat the grill to medium heat, 375-450°F.
Grill chicken undisturbed for 7 minutes per side, or until chicken is cooked through. (An inserted thermometer should read 165 degrees F.)
Remove chicken from grill and let rest 5 minutes before slicing.