Preheat the oven to 180 degrees C, 360 F or Gas mark 4

Add the plain flour and the lemon zest and mix lightly until it just comes together.

Pull together into a dough and then divide into 20 small balls.

Place the balls onto two baking trays making sure to spread them apart.

Dip a fork in a cup of water and use the fork to flatten each cookie.

Bake for 15 minutes until they turn a pale golden colour.

Cool on a wire rack.