Hilsha mustard-posto(kaskas) gravy

Ingredients:  Hilsa- 4pcs(100gm each), Mustard paste- 4tsp, posto(kaskas) paste- 2tsp, Salt- As per requirement, Turmeric powder- 1/2tsp, Green Chilli pieces- 1tsp, Whole green chilli- 2 nos., Mustard oil- 3tsp, Black seed- 1/5tsp, Water- 1 and ½ cup, Chopped Coriander leaves- 1tsp.

Process:  Marinate the fish pieces with one pinch of turmeric powder and salt and left aside. Heat 2tsp of mustard oil in a frying pan, then fry these fish pieces lightly and keep these aside. Next, stir black seed and green chilli pieces in the same oil thoroughly, then add salt, turmeric powder, mustard paste and posto(kaskas) paste and stir it for 1 minute. Add water to it, then add the fried fishes and whole green chilli and boil it for a while. Switch off the oven and add 1tsp raw mustard oil to the preparation. Garnish the preparation with coriander leaves and leave it for 5 minutes. Hilsha mustard-posto gravy is ready to serve with steamed rice.