Wash fish and put in large bowl. blend garlic, yoghurt, tandoori masala and black salt till smooth paste, add oil in it. marinate the fish with the smooth paste. keep for half an hour.
Transfer the marinated fish to shallow baking dish and bake uncovered in a preheated oven for 25 minutes. Arrange the fish in serving tray, garnish with shredded lettuce and sprinkle lemon juice on the fish.
Serve with lemon rice.