Sri Lankan fish curry

1) Put the monkfish in to a glass or ceramic bowl with 1 tsp turmeric, lime zest and juice and a large pinch of sea salt.
2) Mix together to coat the fish, then marinate in the fridge for at least 1 hour.
3) Heat a large casserole pan over a medium–high heat and add the oil, onion, ginger, garlic, chillies and curry leaves.
4) Cook for 5 to 10 minutes, or until the onion is softened.
5) Meanwhile add the rice to a pan with 100ml of the coconut milk and 300ml of salted water, then cook according to the packet instructions.
6) Smash the spices in a pestle and mortar, and then stir them into the pan and fry for 1 minute.
7) Stir in the chopped tomatoes, tamarind paste, the remaining coconut milk and 100ml of water
8) Bring to a simmer for 10 minutes, or until the tomatoes begin to break down and the sauce reduces.
9) Add the monkfish to the sauce and simmer until the fish is cooked through and opaque.
10) Serve with the rice.