Season prawns with salt and tapioca flour for 5 minutes, then put under running tap water to wash off the mixture. Drain well and dab dry with paper kitchen towels. Use the blade of the cleaver to mash the prawns (do not chop them.)
Add seasoning (A) and ingredients (B) to the prawns. Mix well to combine until mixture turns sticky.
Divide mixture into small portions and make into balls. Flatten then coat in egg white and roll in breadcrumbs.
Deep-fry the patties in hot oil over a medium heat till golden brown and crispy. Serve immediately.