Measure the ingredients, sift the flour, cut the butter into small cubes (it must be fridge cold), and fit your food processor with a dough blade.
Process the flour and butter cubes in the food processor for up to 1 minute until you have a sandy mixture. You may need to stop the processor and use a spatula to detach bits sticking to the sides and bottom of the processor.
Combine the egg yolk, water, and salt (also add the sugar for a sweet shortcrust) in a small bowl and stir gently with a spoon until the salt has completely dissolved.
Pour the liquid ingredients into the food processor bowl and process until a ball of dough starts to form; then, stop the food processor (again, this should take less than a minute).
Clean some space on your kitchen countertop and dust it with a pinch or two of flour. Plonk the dough on the counter and roll it into a smooth ball, then flatten it into a thick disc shape to make it easier to roll later.
Wrap the pastry in plastic film and leave it to rest in the fridge for at least 2 hours.
Remove the shortcrust from the fridge at least 30 minutes before you use it for a recipe. This prevents cracks from forming in the dough and makes it more malleable and easier to roll.
