1. Put the flour, butter and a pinch of salt in a food processor and process briefly.
2. Add half the beaten egg and continue to process. (You might add a little more egg, but not too much as the mixture should be just moist enough to come together.) If making the pastry by hand, rub the butter into the flour until it resembles coarse breadcrumbs then, using your hands, add just enough egg to bring it together.
3. With your hands, flatten out the ball of dough until it is about 2cm thick, then wrap it in cling film or place it in a plastic bag and leave in the fridge for at least 30 minutes or, if you are pushed for time, in the freezer for 10-15 minutes, before using.
Cook’s note:This basic pastry is used in many popular recipes, from mince pies to quiches; it’s also one of the easiest pastries for a beginner to make. The uncooked dough can be frozen or kept in the fridge for a couple of days.