Step 1

Toast all the spice mix ingredients in a dry frying pan for a few minutes until starting to smell fragrant. Tip into a spice grinder and blend to a powder.

Step 2

Mix the lime juice, turmeric and chilli powder in a large bowl with a pinch of salt. Add the fish pieces and carefully toss in the marinade. Cover and chill.

Step 3

Whizz the chillies, ginger and garlic in a small blender until you make a paste. Add 1 tbsp water if you need to, to help blend.

Step 4

Heat a little oil in a large wide pan or deep frying pan and fry the chilli paste for a minute. Add the spice mix, fry for another minute, then add the onion, mustard seeds and curry leaves. Fry for 5 minutes. Add the tomatoes and fry until they start to break down, then add the coconut milk and stock. Simmer for 10 minutes until thickened slightly. Season, and add the tamarind paste.

Step 5

Remove the fish pieces from the marinade, and add to the pan, tucking them into the sauce. Gently poach for 5 minutes until the fish is cooked and starting to flake. Serve with steamed rice.