Add salt and turmeric to washed and cleaned fish. Set aside for 15 mins.
Heat 2 tbsp mustard oil in a pan and lightly fry the fish (approximately 2 mins on each side). Remove and keep aside.
Grind poppy seeds and mustard seeds with chili and turmeric powder into a smooth paste. Now add 1/2 cup water to the paste.
Add the remaining mustard oil to the pan. Once hot, temper with green chilies.
Add the diluted mustard paste to the pan. Adjust salt and cook over low heat until oil separates.
Add the fried fish and cook over low heat until most of the water has evaporated.
Serve with steamed white rice.