Soak the mustard seeds in ½ cup of water for 30 mins.
Drain the mustard seeds from the water. In a spice grinder, add the remaining ingredients and grind, adding water if/as needed, until a bright yellow paste forms.
For the Shorshe Chingri Bhapa
In a bowl combine mustard paste, yogurt, salt, turmeric and 1 tbsp of mustard oil and mix thoroughly. Dilute the paste with water if/as needed.
After the spice mix is made, put in peeled and deveined prawn, and split chillies and mix well.
In a small steel container, pour in the contents and top with remaining mustard oil.
Heat water in a large pan or wok and place the container in, making sure at least half of it is submerged. Cover and continue to cook in rolling boil for 12-15 mins.
