Cut the shallot in half lengthways, then peel it and cut it into half-moon shapes approximately 2-3mm (⅛") thick.
Remove the tough stems from the lime leaves and discard them, and finely shred what's left.
Separate the coriander leaves from the stems and chop the stems as finely as you can.
Cut the tough stems from the Thai basil leaves and cut them as finely as you can.
Top and tail the sugar snap peas.
Place the stems of the Thai basil and coriander into a pestle and mortar and grind them into a paste.
Heat a wok over a high heat and when hot, add the oil. Add the lime leaves, slit green chillies, and shallots, then fry for 30 seconds.
Add in the Thai green curry paste and gook for another minute.
Pour in the fish stock and add the pounded stems of the coriander and Thai basil, and allow to simmer gently for 10 minutes.
Add the coconut milk, fish sauce, brown sugar and juice of the lime and have a taste, adjust the flavours to your preference.
Once you are happy with the sauce, add the fish and allow it to poach for 4-5 minutes.
Add in the sugar snap peas and cook for another 1-2 minutes.
Roughly chop the Thai basil and coriander leaves. Finally, add the fresh coriander and Thai basil and cook for a final minute, taking care not to break up the fish.