1½tbspblack mustard seeds soaked in 2 tbsps of water for an hour
2tsppoppy seeds soaked in water with the mustard seeds
3-4green chilliesas per your preference
1-inchpiece of ginger peeled
Wash the fish and pat dry to remove all moisture. Rub with turmeric and a teaspoon of salt and set aside for 15 minutes.
While the fish rests, make the spice paste.
Drain the mustard and poppy seeds (taking care that they don’t flow out with the soaking water), and grind together with all the other masala ingredients in a coffee grinder (using a little water if necessary) to form a thick paste. A coffee grinder or a small food processor is better at pulverising the tiny poppy seeds that may escape the blades in a large container.
Heat a tbsp of oil in a frying pan and fry the fish ( 2 or 3 pieces at a time), for 30-40 seconds on each side. Remove and rest.
Add another tsp of oil to the same pan and add the whole mustard seeds and curry leaves so that they pop and crackle.
Turn down the heat and put in the spice paste. Stir and cook the paste for 5-7 minutes till oil starts to separate from the mixture. It's important to keep the flame down to ensure that the masala doesn’t burn. Sprinkle a little water if it sticks to the pan.
Once the masala is cooked, pour in the coconut milk and toss in the slit green chillies and simmer for 3-4 minutes.
Now gently slip in the fried fish and cook on low simmer for 3 minutes or until the fish is just done.
Prep time does not include time taken to soak the mustard seeds.