Instructions
1 To make green curry paste, place the chillies, lemongrass, coriander leaves, ginger, onion, garlic, lime zest and lime juice into a food processor, process to a coarse paste.
2 Crush the peppercorns, coriander seeds and cumin seeds in a mortar and pestle (if you don't have one, use the end of a rolling pin or a knife handle and a sturdy old mug to crush the spices). Add to the processor and process to a paste. Set aside.
3 Place the evaporated milk or coconut cream into a medium saucepan with 1 tablespoon of curry paste, heat gently and taste. Add more curry paste if desired.
4 When the sauce is to your taste, add the pieces of fish and cook for around 12 minutes. Stir gently from time to time. (Evaporated milk products have a tendency to stick to the bottom of the pan so be especially careful if using those products.)
5 Dissolve the cornflour in a little bit of water and stir into the curry to thicken it slightly. The flavour is in the sauce so I prefer to keep it quite liquid and I serve separate bowls of steamed vegetables and rice that can then be dunked into the curry. You can thicken it more if you prefer and serve it over the rice instead.