HEAT greased grill to medium. Pour 1/2 cup dressing over chicken in shallow glass dish; turn chicken over to evenly coat both sides of each breast. Refrigerate 15 min. Remove chicken from marinade; discard marinade.
GRILL chicken 5 to 7 min. on each side or until cooked through (165ºF). Slice chicken.
COVER platter with spinach; top with chicken, fruit, onions and remaining dressing.