In a strainer add 2 tbsp of yellow and 2 tbsp black mustard seeds (50:50), wash under running water, and grind with one green chilli to a smooth paste by using your food processor. From this mustard paste use 4 tbsp for making Kochu patai Ilish. You can use rest (if anything left) 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 3½ tbsp of it and follow the package instructions for dissolving.

Wash and add poppy seeds in a food processor with some water. Make a paste which would be thick, not watery. So, stop the food processor in between and keep adding a little amount of water. Finally, it will form a smooth paste. Now add the grated coconut and green chillies into this, blitz again, the mixture will become coarse, keep aside.

In a bowl, add poppy seeds-coconut paste, mustard paste, turmeric powder, kalojire/nigella seeds, salt, and mustard oil. Mix well, adjust the consistency of this paste by adding some water into it. I added 2 tbsp of water, this spice paste should be medium-thick, not watery, so add water carefully. Keep aside.

Wipe the taro leaves clean with a wet kitchen towel or you can alternately wash them under running water. Cut off the stems attached to the leaves. Grease the upper side of the leaves with mustard oil, you can use a pastry brush.

Place two Taro leaves (greased side up) on the kitchen counter by slightly overlapping each other (see the picture for reference) from the centre.

Dip a piece of Hilsa in the spice paste. Then place the spice paste coated Hilsa piece in the middle of the leaves. Wrap & fold the leaves gently from all the sides and make a parcel by tying with cotton thread. 

Oil grease the base of the MultiPot steamer basket by using the pastry brush. Arrange the Hilsa leaf parcels inside of the basket.

Pour 1 cup of water to the stainless steel inner pot.

Place the steam trivet inside, upon the trivet place the steamer basket carefully.

Lock MultiPot lid in place and set steam vent handle to sealing. Select Pressure Cook and cook on High Pressure for 5 minutes.

When the cooking cycle is complete, turn steam vent handle to Venting to quick-release pressure.

Remove lid and take out the Hilsa Paturi (Hilsa leaf parcels) gently with a spatula and transfer them to a plate.

The Kochu patai Ilish is done, serve hot with steamed rice.

Discard the cotton threads before serving. Enjoy the Hilsa and soft mustard slathered taro leaves both with rice!