List of ingredients...
In a small bowl, lightly whisk the egg with a fork.
In a large bowl, sift together the flour, salt and sugar and mix through.
Cut the butter into 1 cm cubes (ensure it is chilled) and place in the bowl.
Rub in the butter with your fingertips into the flour/sugar mixture until you have a crumbly mixture similar to breadcrumbs (see Notes).
Make a well in the centre and pour the whisked egg into it.
Slowly work the mixture with the spatula until it mostly combines (see Notes).
Either in the bowl or on a cool bench, use one hand to bring the mixture together until it holds. Do not over work (see Notes).
Shape into a ball and flatten it slightly, wrap with plastic wrap and fridge for at least 60 min before use.