DO-AHEAD TIP: Marinate chicken overnight or for at least 1 hour (see recipe). Toast coconut, if desired.
Place chicken in a zipper-topped plastic bag. In a small bowl, combine next 9 ingredients (garlic through black pepper).
Pour mixture over chicken. Seal the bag and turn to coat. Refrigerate overnight, or for at least 1 hour. Preheat grill to MEDIUM. Lightly oil the grill grate.
Remove chicken from bag and shake off excess marinade (reserving marinade). Grill over indirect heat for 15 to 20 minutes, turning occasionally, until chicken juices run clear.
Watch carefully to prevent burning! Meanwhile, transfer marinade to a small saucepan over medium heat. Bring to a boil then reduce heat and simmer until mixture is reduced by half.
Top grilled chicken with sauce and toasted coconut then serve over fresh spinach - enjoy!!!