Let the mustard seeds crackle. Crush the ginger and garlic in a mortar and pestle. Add it to the pan along with chopped shallots/small onion and slit green chilies. Add in the salt. Sauté till the onions are soft and starting to brown. Make a paste of Ajmi fish curry powder. Add few tablespoons of water and make a thick paste. Add the paste to the curry and sauté well for 3-4 minutes until the masala paste is completely cooked. Streaks of oil will start appearing from the mixture. Its a sign that the masalas are cooked. Once the paste is well cooked, add in half a cup of water. Soak the Kodampuli in a cup of water for 5 minutes. Add in the soaked kodampuli along with the water used. Add in a cup of second pressed coconut milk. Also add in the fish to the pan. Close the pan with a lid and let the curry simmer for 6 minutes. Remove the curry from heat and allow the curry to rest for at-least a couple of hours so the flavours mature. It tastes better the next day.