In a bowl, whisk together the flour and salt. Add the butter and rub between your fingertips, incorporating the mixture as you work, until the butter forms flaky pieces. Gradually add the water and combine until just moistened. Pieces of butter will remain and the dough will be soft and sticky.
On a lightly floured surface, roll out the dough into an 8 x 13-inch (20 x 33 cm) rectangle. Brush off any excess flour. Fold the dough into thirds widthwise, then fold in half to create a square. Cover in plastic wrap and refrigerate for
45 minutes or until firm.
Cut the dough in half. Cover each piece in plastic wrap. The dough will keep for 2 days in the refrigerator or 1 month in the freezer.