In a blender, add Mustard seeds, poppy seeds, coconut, 2-3 greens chilies and a pinch of salt with little water, grind to smooth paste

Add sugar, turmeric powder and lime juice to it, check for seasoning and grind to smooth consistency

Coat the fish pieces gently with the marinade and rub them with your fingers. Rest aside for 30 minutes or Refrigerate for 2 hours

Once the marination is done, pour in the 1 tbsp mustard oil and mix it well

Cut the banana leaf into 8 inches square and pass it over flame without burning it, this will help in folding the leaves

Rub the mustard oil on glossy part of the leaf. Place a piece of fish at the centre and add some marinade to it

Place one green chilli on top of it.Fold the leaf from each side and make it a square parcel

Wrap it with the thread so that it doesn’t open while cooking, Wrap the rest of the fish pieces in similar way, there should be individual parcels for each piece

Heat water in steamer.Add the parcels into the steaming rack and steam for 10 minutes over medium heat

Remove from steamer, discard the threads from the parcels

Open and serve hot with rice