Mix the flour and salt (and sugar, if using) together in a bowl.

Cut the butter into the dry ingredients using a pastry blender, two knives, or your fingers, until the mixture resembles coarse meal or tiny peas.

In a separate bowl, whisk the egg yolk and 2 Tablespoons water together.

Add the liquid to the dry ingredients and blend until the pastry is smooth and holds together in a ball.

If you are using a food processor, process the flour, salt (sugar, if using) and butter pulsing quickly, until the mixture resembles coarse meal. Turn the processor on and add the egg yolk/water mixture thru the feed tube, processing until the dough balls up around the blade.

On a piece of plastic wrap, form the dough into a disk, wrap with plastic wrap and refrigerate for at least 20 minutes.

This dough can be rolled out with a rolling pin, but the dough must be chilled for at least 30 minutes before rolling.

I find the easiest way is to pat the dough into a pie, tart, quiche, or springform pan using my hands.

Pull pieces of dough from the chilled ball and press them over the bottom and sides of the pan, using your fingers and the heel of your hand. The dough should be thick enough to hold the filling, but be careful that it is not too thick around the bottom edge or the finished tart will seem gritty and coarse.

If time allows, cover the pastry-lined pan and refrigerate it before filling and/or baking.

Bake as directed in the filling recipe, or prick the bottom with a fork and bake it unfilled for 12 minutes in a preheated 425º F oven. If you are using a springform pan, do not remove the sides until you are ready to serve the tart.