Yield 1 crust (enough for 1 large tart or pie, 1 galette, or 18 mini tarts)
Cut the butter into small cubes and arrange on a small plate. Freeze for 20 minutes.
Add the flour and salt to a food processor, then pulse to combine. Add the butter and process for 10 continuous seconds, until the mixture looks like coarse breadcrumbs.
Add the egg and process for 5 seconds. Add the ice water and process for 20 seconds. The dough should now start clumping together. Turn the mixture out onto a work surface. The mixture will easily hold together when pressed. Using your hands, gather the dough into a ball then flatten into a disk, kneading it as lightly as possible.
If you’re making shortcrust pastry right before you need to use it, gather it into a disk, set it on a lightly floured surface, and roll it out to the required size. Ease into to a pie or tart pan, lay flat on a baking sheet, or cut out and fit into muffin pans if making tartlets. Refrigerate for 30 minutes to an hour. Use as instructed by the recipe.
You can alternatively wrap the ball of shortcrust pastry in plastic wrap and refrigerate it for 3 days, or freeze for 1 month.
Bring refrigerated shortcrust pastry back to room temperature at least 30 minutes before rolling. Thaw frozen shortcrust pastry overnight in the refrigerator, then bring back to room temperature at least 30 minutes before rolling.
Recipe by Food Nouveau at https://foodnouveau.com/recipes/how-tos/foolproof-shortcrust-pastry-food-processor-method/