Slice the prawns
halfway through the back and spread them out to form
a butterfly shape. Mix together the soy sauce, wine
or sherry, ginger and salt.
Pour over the prawns and
leave to marinate for 30 minutes. Remove from the
marinade and pat dry.
Beat the egg with the corn-flour and flour to a batter and dip the prawns
in the batter. Heat the oil and deep fry the prawns
until golden brown. Drain well before serving.