If using frozen prawns, thaw by placing them in cold salted water, then drain.
1. Gently twist the head and pull it from the prawn's body.
2. Using your fingers, roll off the shell from the underside with the legs still attached to the shell.
3. Gently squeeze the tail and carefully remove it. If you wish, the tail flap can remain attached to the body to enhance presentation.
Using your fingers, strip out the black intestinal tract (vein) completely. For green (raw) prawns, you may need to use a small knife to make a shallow cut along the back before removing the intestinal tract.
This is usually done on green prawns. It is used to increase both the visual appeal and the apparent size of the prawns.
Cut the shelled prawn lengthwise, almost right through the flesh and along its entire length, traditionally along the stomach. Alternatively, you can cut along the back of the prawn to give a circular shape and larger appearance.
Deveining can be done at the same time as the butterflying. The tail is traditionally left on for butterfly prawns.