HEAT barbecue to medium-high heat.
COMBINE tomatoes, 2 Tbsp. dressing and garlic. Place fish in centre of large sheet of double-layer heavy-duty foil sprayed with cooking spray. Sprinkle with black pepper; top with tomato mixture. Fold foil to make packet.
GRILL 8 to 10 min. or until fish flakes easily with fork. Meanwhile, toss vegetables with remaining dressing; grill 5 min. on each side.
CUT slits in foil to release steam before opening packet. Sprinkle fish with cheese. Serve with vegetables and quinoa.
serving size = 1/2 recipe (350 g)