1.   500 gms Hilsa fillets
2. half tsp turmeric
3. 6 tbsps of black mustard 
4. couple of green chillies, salt 
5. 2tsp khus-khus / poppy seeds
6. 4 tbsps mustard oil.
7. Banana leaves 


Wash hilsa pieces thoroughly and rub it with salt , turmeric, ground mustard ( while grinding add a chilli and salt to it ), ground poppy seeds ,  liberal helping of mustard oil . Keep it marinated for about an hour. Wrap the whole thing in  banana leaf  and secure it with a string. Grease a tava and  roast the packet on it on  a very very low heat. The packet has to be turned several times. Keep frying till the leaf is totally burnt. It should take about 20 minutes. Remove it from fire and cool . Unwrap it , pour a little bit of mustard oil ( half a tsp ). Heat it in a micro-wave before serving. Serve it with plain rice.

One can bake it also....Preheat the oven to 160  C. Put the packet on a tray and push it  in the oven and bake it for 20 minutes.