1.To make caponata, heat oil in pan; cook eggplant, capsicum, onion, celery and garlic about 5 minutes, or until softened. Add tomatoes and vinegar; cook, stirring, a few more minutes. Add olives and capers; simmer 5 minutes.
2.Meanwhile, preheat an oven grill. Place fish on tray and brush with oil; place under grill 2-3 minutes, or until just cooked.
3.Transfer garfish fillets to plate and spoon a generous amount of caponata on side.
4.Sprinkle fish with chopped parsley; garnish with rocket and lemon wedges to serve.