for my reference, from penny

Peppermint Creams
Whisk one egg white until frothy
Beat in about two thirds of the 12oz of sifted icing sugar and a few drops of peppermint essence
Turn out and knead in the remaining icing sugar.
Roll out, to about a quarter of an inch thick and cut into shapes
Leave to set until firm and dip half of the round into melted chocolate.