Mix egg whites and icing sugar. Put aside about five tablespoons of this mixture for the icing. Mix in all remaining ingredients and knead lightly into a dough. Roll out on a sugared board to about 6mm thickness and cut out stars. Place on a greased baking sheet and paint with left-over icing mixture. Leave to dry overnight. Bake in a preheated oven (180°C) for 10 mins.
