Chop the peanuts fairly finely.
Beat the egg and dip the prawn tails in it, roll them in the chopped peanuts, then repeat once again.
Fry in plenty of hot oil for a few minutes. When they have turned golden, serve with the sauce.
Cover the prawn heads with oil and cook over a low heat for 15 minutes, then strain.
Brown the nuts in a frying pan with a splash of oil, stirring constantly, then chop them roughly and mix into the prawn oil.