Spread both sides of fillets with 3 tablespoons dressing. Combine cracker crumbs and pepper in a shallow dish; dredge fish in crumb mixture. Place fish in an 11- x 7- x 1 1/2-inch baking dish coated with cooking spray.
Bake at 400° for 15 to 20 minutes or until fish flakes easily when tested with a fork. Drizzle with 2 tablespoons dressing; top with cucumber and tomato.