Combine flour, sugar and salt. Add the flour, icing sugar, and salt to a food processor and then pulse it until it is combined.
Make the shortcrust. Add the cold butter and pulse again until the mixture resembles fine breadcrumbs. Then add most of the beaten egg yolk and pulse until the dough starts to hold together. Finish by adding the remaining egg yolk and continue to pulse until the dough turns into a big clump. You can add a dash of water, if necessary. Note: if the dough is too dry it will be crumbly, it should hold together when pressed.
Chill the dough. Transfer the dough from the food processor to a clean work surface and use your hands to form into a ball then press down so it looks like a thick disc. Wrap the disc in plastic wrap and refrigerate for at least 30 minutes or up to 2 days.
Bring the dough to room temperature. You want to take the dough from the refrigerator and let it sit at room temperature for up to 10 minutes. You'll require this to soften the dough a bit, so that you can roll it out.
Roll the dough. Roll out the disc using a rolling pin. If your dough is sticking to the surface or to the rolling pin add a bit more flour as necessary. Roll it until it’s about ⅛ of an inch in thickness.
Place dough in tart pan. Place the dough lightly into a 9-inch fluted tart pan with a removable bottom. I usually roll it on the rolling pin and unroll it over the tart pan. Cut off any excess dough (see Tips for an easy way to do this). Place the tart pan back in the refrigerator for another 30 minutes.
Preheat the oven. Preheat the oven to 375°F.
Prick pastry and add pie weights. Remove the tart pan from the refrigerator and prick the bottom of the pastry with a fork. Place a piece of parchment paper onto the pastry and fill it with pie weights or dried beans.
Bake and remove pie weights. Transfer the tart pan to the oven and bake for 15 minutes. Remove the pie weights and parchment paper carefully and bake for an additional 5 minutes.
Allow crust to cool. Remove the tart from the oven and let it cool.