Using a food processor, beat the flours and salt into the potato.

Add the fat, cutting into small pieces with a knife before beating into the flour.

Work the dough lightly and briefly into a ball, wrap in cling film and refrigerate for 30 minutes.

Knead the dough on a cold floured surface with the heel of the hand for 1 to 2 minutes when it should be smooth and putty like.

Refrigerate for another 30 minutes before rolling out on a cold floured board to the required shape. Keep moving it round on the board so that it does not stick.

Preheated oven 425°F 220°C Cook empty pastry shells for 15 to 20 minutes or until golden brown.