Preheat the oven to 180˚C/350˚F
Line two baking sheets with baking paper.
In a medium mixing bowl cream (beat vigorously with a spoon) the butter, sugar, and lemon zest until pale and fluffy.
Stir in the wholemeal flour and white flour: use a spoon at first, then lightly with your hands until it comes together to form a dough.
Roll the dough out between two sheets of baking paper, to a thickness of ½ cm/0.2”, then cut out your shapes.
Place the shapes onto your lined baking sheet leaving room in between the biscuits.
Gently reroll any scraps and repeat the process until all the dough is used up.
The last scraps of the shortbread dough may just have to be an odd shape, but that is a cooks perk!
Bake the shortbread on lined baking sheets for 10-12 minutes, until lightly golden.
Leave on tin for a couple of minutes and then transfer to a wire rack to cool completely.
Once cool, you can ice them.