Sift flour onto a pastry board, cloth or dough bowl and make a large well in the center. Pound butter to soften slightly or have at room temperature. Place butter, egg yolks, salt and smaller amount of water in the well and work together with the fingertips of one hand until partly mixed. Gradually work in flour, pulling dough into large crumbs using the fingertips of both hands. If the crumbs are dry, sprinkle over a Tbsp more water. Press dough firmly together - it should be soft but not sticky. Work on a lightly floured board, pushing dough away with the heel of the hand and gathering it up with a dough scraper until smooth and pliable. Press dough into a ball. Wrap in foil or plastic wrap and shill for 30 minutes. It can be stored tightly wrapped in the refrigerator for up to 3 days. Roll Pastry to about 1/4" thickness in a rectangular shape. Place pastry on an oiled baking sheet. Crimp edges of pastry if desired. Beat an egg yolk with a pinch of salt and brush over the entire pastry. This is called "egg glazing" and helps the filling adhere to the pastry. Prick pastry with a fork in several places to prevent bubbles from forming while baking.