Hot-water crust pastry
Put the cubes of butter and the water in a medium-sized saucepan and heat gently, stirring occasionally, until the butter melts, then allow the mixture to come to a rolling boil.
Meanwhile, sift the plain flour and the pinch of salt into a large bowl. Make a well in the middle and add the beaten egg. Pour the hot liquid from the saucepan into the flour mixture and stir with a wooden spoon to mix.
Spread the mixture out on a large plate with the wooden spoon and allow it to cool - this should take about 15 minutes - then wrap the pastry in cling film and place it in the fridge for 30 minutes until it is firm. Use according to the recipe you are making.