Apply salt to fish and rinse it well. Drain thoroughly. Mix all the ingredients except oil. Apply to the fish. Keep this aside for 10 minutes. It absorbs flavors well.
Heat a small pan with oil or ghee. When the oil turns hot enough fry it for about 3 to 4 minutes. Then flip it to the other side. Fry again till it is fried completely. Add curry leaves and fry until crisp. Drain to a kitchen tissue.
Serve with onion wedges.