1. In a medium bowl whisk the marinade ingredients.
2. Place the breasts on a large, rimmed plate. Spoon or brush the marinade over the breasts, turning to coat them evenly. Cover with plastic wrap and refrigerate for 1 to 2 hours.
3. Prepare the grill for direct cooking over medium heat.
4. Brush the cooking grates clean. Grill the chicken, smooth side down, over direct medium heat, with the lid closed as much as possible, until the meat is firm to the touch and opaque all the way to the center, 8 to 12 minutes, turning once or twice. Serve warm.