HEAT barbecue to medium heat.
COVER half the barbecue grate with large sheet of heavy-duty foil. Meanwhile, place chicken in shallow dish. Drizzle with 2 Tbsp. dressing. Refrigerate 10 min.
PLACE chicken on uncovered side of barbecue grate; grill 6 min. Meanwhile, combine remaining dressing, tomatoes, cheese and basil.
TURN chicken over; place on foil-covered grate. Top with tomato mixture. Grill 8 min. or until chicken is done (170ºF).
serving size = 1 topped chicken breast (210 g)