In a small bowl, whisk together the water, milk and yeast.
In a large bowl, combine the flour, sugar and salt. Using your fingertips, incorporate the butter into the flour until flaky. Gradually add the milk mixture and combine just until the dry ingredients are moistened, making sure to leave large pieces of butter intact. The dough will be soft and sticky.
On a lightly floured surface, roll the dough out to form a 13 x 8-inch (33 x 20 cm) rectangle. With a pastry brush, remove any excess flour. Fold the dough in 3 widthwise. Fold the dough in half lengthwise to form a square. Cover with plastic wrap. Refrigerate for 8 hours or overnight before using.