Heat the oven to 190c/fan 170c/Gas 5. Beat the butter and sugar together until asoft and pale, creamy colour. Gradually beat in teh egg. Mix the flour, making a smooth dough.

Lightly dust a work surface with flour and quickly roll out the dough. Press out star shapes, place in a baking sheet and cook for 8-10 mins until golden at the edges. Carefully lift with a palette knife and cool on a wire rack.

Put the icing sugar in a bowl and add enough hot water to mix the icing sugar to a stiff consistency. Spoon the icing on to the biscuits and smooth out.Leave to harden.