In a strainer add 3 tbsp of yellow and 3 tbsp black mustard seeds (50:50), wash under running water, and grind with the green chillies to a smooth paste by using your food processor. From this mustard paste use 7-8 tbsp for making Ilish Paturi. You can use the rest of the paste for making mustard-based fish or vegetable curries.

Or else, you can use ready to use mustard powder (Sunrise brand). If cooking with the mustard seeds powder, use 5 tbsp of it and follow the package instructions for dissolving.

If you're using ready to use mustard powder then make the green chilli paste separately in the food processor by adding the green chillies and some water.

In a bowl add mustard paste, mustard oil, turmeric powder, salt, nigella seeds, and green chilli paste, mix well. Remember this mixture should be thick, not watery. Add this mix to the freshly washed pieces of Ilish. Mix gently, keep aside.

Heat the banana leaf sheets from one edge to another (glossy side down) over low flame for a few seconds. This is for easy folding, care should be taken not to burn out the leaves.

Cut the banana leaves into rectangles. Keeping in mind that you need the leaf pieces to be spacious enough to wrap, and parcel one piece of Ilish. Clean the leaf pieces with a wet kitchen towel. Grease the upper part of the leaf sheets with mustard oil.

For making the fish parcel; place 1 piece of banana leaf horizontally, and place another piece of banana leaf vertically on top of it forming a ‘+’. Now place 1 piece of fish in the centre of this. Fold the end of the banana leaves, wrap and make a parcel. Tie with cotton thread. Continue the same process for every piece of fish.

Grease an iron tawa (not nonstick) with mustard oil. Place the fish parcels/paturi on tawa.

Cook for 20 minutes over low heat. Flip the parcels in between. Let the parcels turn dark brown in color. Remove from the heat. Your delicious Ilish Paturi is ready to devour. Serve hot with steamed rice. Enjoy!