Chop the prawns into small pieces, but not too finely. Put them in a bowl and stir in the white pepper and salt.
Soak the bread in cold water, then squeeze out all the liquid, break it into small lumps and place in a bowl. Add the onion, garlic, chillies, lime juice and coriander and knead until evenly combined. Add the prawns and mix until evenly distributed.
Heat the oil in a deep fryer or a heavy-based pan over a medium–high heat. Shape a piece of the mixture into a 5-cm croquette and test-fry one croquette; when cool enough to eat, taste and adjust the seasoning, adding more salt, pepper or lime juice if required.
Shape the remaining mixture into 5-cm croquettes and fry in the hot oil in small batches, turning frequently, for 2–3 minutes. Drain on kitchen paper.
Serve with any dipping sauce you like, such as chilli sauce or tomato ketchup, or serve some Pineapple and Chilli Chutney (page 228) on the side.