First make the pastry. Sift the flour into a large mixing bowl and stir in the salt. Rub in the butter with the fingertips until the mixture resembles coarse crumbs. Add all but 1–2 spoonfuls of the water and cut it into the mix with a knife. Gather together with your hands and, if it feels too crumbly, add just a little more water and repeat the cutting-in process until it