Put the flour and the sugar in a circle and the soften butter, egg yolks, and the grated lemon peel in the center.

Beat the eggs in the center of the circle with a fork, slowly mixing in the flour and the sugar.

Once the ingredients are mixed together, rapidly knead the short pastry without mixing it, but only pressing it until the color is uniform. 

The short pastry must not be kneaded too much or it will loose its shortness.

Let the short pastry rest for at least half an hour, covered in a wet napkin.