Start by making the masala spice blend. Warm a non-stick frying pan over a medium heat. Put all the spices into the pan and gently stir, toasting them until you get a nice aromatic smell. Take off the heat and blend in a spice grinder until you have a fine powder. Tip the spice into a mortar, add the sugar, red pepper flakes, garlic, ginger, shallot and tamarind paste, and mash together to form a paste.
Pour a little vegetable oil into a wok over a medium heat. Add the spice mixture with the tomato purée and fry until the paste really starts to bubble. Add the coconut milk and simmer for a couple of minutes. Stir in the cider vinegar and season with a little salt. Add the sliced fresh chilli, then the monkfish and prawns and gently cook until the fish is cooked through.
In the frying pan you used to toast the spices, heat a little vegetable oil and quickly fry the mustard seeds and curry leaves until they start to pop. Scatter over your curry and serve with steamed rice and flatbreads.
Recipe by appetite magazine at https://www.appetitemag.co.uk/goan-monkfish-prawn-curry/