In the bowl of a stand mixer fitted with the paddle attachment, mix together the flour & the sugar.
With the mixer on slow, add in the chunks of butter. Beat together until the butter breaks down. The mix should resemble breadcrumbs mostly, but with some larger pea size pieces of butter. Pour the ice cold water into the bowl & mix together quickly until it just starts to form a dough, but there are some unincorporated bits in the bottom of the bowl.
Handling the dough as little as possible, tip the contents out onto a lightly floured surface & bring everything together on the bench, very lightly kneading it. Shape the dough into a large rectangle & use a rolling pin to roll it out to double it's size. Perform a single fold in the dough by folding the top third down into the middle, then the bottom third up over the first, as you would a letter.
Using a sharp knife, gently cut the dough in two. Lightly shape each piece into a disk shape, wrap both tightly in cling film, and rest in the fridge for at least 2-hours.
Lightly grease a 9-inch pie tin with butter. On a lightly floured surface, roll one of the pie discs out to a large circle place in prepared tin. Trim the edges, and crimp if desired. Place in the fridge.