Oily fish goes well with curry, particularly with the flavours of tomatoes, tamarind and curry leaves.
Heat the oil in a heavy-based saucepan or karahi over a medium heat. When hot, add the mustard seeds and fry for 30 seconds, then stir in the onion and garlic and fry gently for about 10 minutes, or until softened and lightly golden-brown.
Add the curry leaves, chilli powder, coriander and turmeric and fry for two minutes, then stir in the tomatoes, tamarind liquid, green chillies and salt and simmer for about 10 minutes, or until rich and reduced. Add the fish, cook for a further five minutes or until just cooked through, and serve with plain rice.
