Pre heat oven to 160 / 320F
Beat the butter and icing sugar till light and fluffy with the vanilla
Add the egg and beat well then add the sifted dry ingredients and mix till combined. Then chocolate and nuts.
Roll into a log and chill, slicing into 1 cm thick rounds. Or alternatively roll into balls and flatten slightly on a paper lined tray.
Decorate each biscuit with a pistachio placed in the centre.
bake for approx 12-15 minutes.
Cool