To begin making the Doi Ilish Recipe, firstly marinate the fish with turmeric and salt. Keep it aside.
Heat oil in a heavy bottomed pan. Once the oil is mildly hot, add the fish and shallow fry them. Once done, take it out of the pan and keep it aside to cool it down.
Once done, add the fried fish pieces in a mixing bowl along with turmeric powder, red chilli powder, whipped curd and just a pinch of salt. Mix everything properly and keep it aside for 10 minutes.
To the same pan, add the rest of the oil, when smoking hot, throw in the nigella seeds and green chillies. When they stop spluttering, turn the heat to low and gently slide in the fish along with the marinade.
Cook for a couple of minutes till the curd starts to release oil. Now add a little warm water to the mustard paste and add it to the yogurt mixture. Add this micxture to the pan and simmer for 4-5 minutes. Adjust the salt, give it a mix and serve hot.
Serve Doi Ilish Recipe along with Steamed Rice and Kachumber Salad for a weekday meal. You can also make this delicious Bengali Style Fish Gravy for your house parties with other Bengali dishes.