DO-AHEAD TIP: Marinate chicken overnight or for at least 4 hours (see recipe)
Prepare pesto: In a food processor or blender, pulse first 5 ingredients (basil through ghee) until smooth.
Place chicken in a large zipper-topped plastic bag and pour pesto over the top; seal the bag and refrigerate overnight or for at least 4 hours.
Preheat outdoor or indoor grill to MEDIUM-HIGH. Coat the grill quickly with coconut oil then remove chicken from marinade (discarding marinade and bag) and grill for 4 to 7 minutes per side or until cooked through.