Start by drizzling 1/2 cup (120 ml) of the ice-cold water (but not the cubes, if there are any left!) over the butter and flour mixture. Using a rubber or silicon spatula, gather the dough together. You’ll probably need an additional 1/4 cup (60 ml) of cold water to bring it together, but add it a tablespoon as a time. Once you’re pulling large clumps with the spatula, take it out and get your hands in there.