This is truly a “whole” lemon tart, however I must warn you that if you have a lemon with unusually thick skin, your tart may come out a little bit bitter. If you notice after slicing into your lemon that the white pith is thicker than 1/4 inch thick, it might be best to remove it. Use a knife to remove the zest and then the white pith. Add the zest and flesh to the food processor, throw the pith away.