PREHEAT oven to 400°F. Cut opened package of fish into 4 equal pieces.
MIX zucchini and tomatoes in 9-inch square baking dish; top with fish. Spoon 1 Tbsp. of the dressing over each piece of fish.
BAKE 15 minutes; sprinkle with cheese. Bake an additional 8 to 12 minutes or until fish flakes easily with fork. Serve with lemon wedges.