Mix the fish pieces with salt and turmeric powder. On a frying pan add 1 tablespoon of oil and fry the fish pieces. Set aside the fried fishes.
In the same pan, add another 1 tablespoon of oil. Also add the ginger and green chili pastes, yoghurt, salt and mustard paste. Cook until the water of the yoghurt dries and the oil starts to float on top.
Now add the fried fish pieces and allow the curry sauce to soak into the fishes. Reverse the sides of the fish so that all sides of the fish pieces are soaked well in the curry. Cook for 15-20 minutes.
Now sprinkle the mawa, sugar and raisins all over the fish curry.
Put the lid on for 5-6 minutes and allow the steam to do the final part of the cooking.