Rough chop the nuts and chocolate.

Cream the butter and sugar together until soft and pale.

Add the flour, chocolate and nuts. The dough should come together but add up to a tablespoon of milk if you need to.

Transfer the mixture to a large piece of clingfilm in a flatish shape.

Put the dough in the fridge for 30 minutes to rest.

Line 2 baking sheets with parchment paper or reusable silicon.

Unwrap the dough but leave on the cling film and cover with another piece.

Roll the dough out to about 1 cm thick.

Cut 12 pieces with a knife, about 10 cm square.

Place into an oven preheated to 180 C / 165 C Fan / 350 F/Gas Mark 4 for 10-12 minutes, or until lightly browned.

Let the chocolate shortbread rest on the baking tray for a few minutes then transfer to a cooling rack.