Clean the fish. Make deep cuts an inch apart all over the fish.
Mix beaten yogurt with all the other ingredients except garam masala. Marinate the fish in this mixture for 4 hours in the refrigerator. Take the fish out of the refrigerator 15 minutes prior to frying and set aside. Preheat the oven for 400°F and put the fish in a baking dish and bake for 5 minutes. Take it out and brush with oil & sprinkle the garam masala on top of it. Then bake it until it is cooked. Serve hot.