Place the flour and salt into a mixing bowl

Add the butter and rub in using your fingertips until it resembles bread crumbs

Place the egg yolk and 15mls water into a mixing bowl

Whisk to combine and add to the flour

Mix together until the dough starts clumping, adding up to 15mls more water

Turn out onto your work surface and form into a ball

Flatten this into a disc and cover with cling film

Refrigerate for 30 minutes before rolling out as needed