Using a sharp paring knife, cut a few deep slashes into the meaty parts of each chicken leg. Place them in a large, resealable plastic bag and pour in the marinade. Press the air out of the bag and seal tightly. Turn the bag to distribute the marinade. Refrigerate for 4 to 8 hours, turning occasionally.
Place a large foil pan on top of the Flavorizer bars, below the cooking grate. Fill it halfway with room temperature water. Prepare the grill for cooking over medium heat (400°F).
Remove the chicken from the bag, letting the herbs cling to the chicken. Discard the marinade. Brush the cooking grates clean. Grill the chicken above the foil pan, over medium heat, with the lid closed, until the internal temperature reaches 165°F in the thickest part of the breast (not touching the bone), 50 minutes to 1 hour, turning once. Remove from the grill and let rest for 3 to 5 minutes. Cut into thighs and drumsticks, if desired.
