Sift together the flour and powdered sugar.
Cut the butter into the flour and sugar until it resembles sand.
Add the egg and loosely mix the dough.
Dump the dough out onto the counter top and with the palm of your hand, push the dough away from you, crushing it as you go. Repeat 2-3 times or until the dough comes together to form a smooth dough.
Pull into a ball and then flatten slightly. Cover in plastic wrap and let chill in the fridge for about 20 minutes.
After the dough is chilled, place it on a lightly floured worktop. Roll out the dough, moving the dough and making sure there is enough flour so it does not stick.
Transfer to a tart circle or pan and work the dough into the corners. Roll the rolling pin over the top of the tart pan to remove any excess dough. With your thumb, smooth out the dough that may have been pushed down by the rolling pin.
Dock the bottom of the tart shell and put it in the freezer for at least 20 minutes.
After the shell has chilled, place in an oven preheated at 170°c (340°F) for 20 minutes or until the tart shell is golden brown.
Set aside on a cooling rack.