HEAT barbecue to medium-high heat.
BRUSH chicken with 1 Tbsp. dressing. Grill 6 to 8 min. on each side or until done (170°F).
MEANWHILE, grill bread slices 30 sec. on each side or until lightly toasted on both sides.
COMBINE tomatoes, cheese and basil. Toss spinach with onions and remaining dressing; spoon onto serving plates. Top with chicken and tomato mixture. Serve with bread.
serving size = 1/2 recipe (248 g)