Pour the plain flour in a clean blender. Add the caster sugar, a pinch of salt and the ice cold diced butter.

Pulse into a dry crumble. Then add the ice cold water to the flour.

Pulse well until you get a moist dough. Then add extra flour if it is too wet or an extra drop of water if it is too dry. The dough shouldn't be sticky.

Transfer it to a lightly floured surface. Knead the dough quickly for two minutes until it is smooth. Then wrap the dough loosely up in some cling film and let it rest at room temperature until needed again.