(most popular festive  Bengali style  steamed Hilsa with mustard paste and  mustard oil. )

Ingredients:
10 pieces of Hilsa
3 green chilies (or more if you can take the heat)
1/2 cup mustard seeds
pinch of turmeric
2 tbsp grated coconut
salt to taste

Method:
Soak the mustard seeds in some warm water for about 20-30 minutes before grinding them. Marinate the fish pieces in salt. Grind the mustard seeds, 2 green chilies and coconut to a fine paste. Remember to add some salt while grinding the mustard. Add water as needed to make it a smooth fine paste. The mustard gets a bitter taste if you grind without the salt.

Spread the fish out in a single layer in the pressure cooker separator containers. Mix a pinch of turmeric with this paste and pour over the fish such that the pieces are all coated in the paste. The paste should not be very watery. Pour a generous helping of mustard oil on the fish and paste. Put in the pressure cooker and steam for 2 or 3 whistles.