Marinate the Hilsa fish pieces with salt and turmeric powder. Leave them for 10 minutes.
Put a cooking pan on the gas stove and turn it on.
Pour mustard oil into the pan.
When the oil is hot, add black cumin seeds.
Stir a little and add two green chilies.
The ingredients will start fluttering. Reduce the flame.
Add ½ tbl spoon each of turmeric and Kashmiri red chili powder.
Add a little amount of water.
Sauté on a low flame.
After a little while, add mustard paste to the oil. Don’t stir too much as the gravy will turn bitter.
After 5 minutes, pour 1 cup of water into the pan.
After a while, add some salt and the green chilies.
Once the curry comes to a boil, add the Hilsa fish pieces one by one.
Put a lid on the pan and leave it to cook for 10 minutes.
Remove the lid and turn the fish pieces upside down.
Put the lid on and leave it for 5 minutes.
After the fishes are well cooked, reduce the flame further and add 1 tbl spoon of mustard oil. The mustard oil added at the last moment gives the dish a strong and distinct aroma.
Turn off the gas stove. Put the lid once again and leave it for 5 minutes so that the strong flavour of mustard oil does not escape the pan.
Transfer Sorshe Ilish to a bowl. Serve it hot along with plain steamed rice.