Preparation Sift flour with salt into a large bowl and blend in butter with your fingertips or a pastry blender until most of mixture resembles coarse meal with small (roughly pea-size) butter lumps. Beat egg with vinegar in a 1-cup measure using a fork, then add enough ice water to measure 1 cup total. Add to flour mixture, stirring with fork until incorporated. Turn out mixture onto a lightly floured surface and knead gently with heel of your hand just enough to bring dough together. Roll out or pat into a 15- by 9-inch rectangle. Arrange dough with short side nearest you, then fold into thirds like a letter to form a roughly 5- by 9-inch rectangle. Chill dough, wrapped in plastic wrap, at least 1 hour and up to 6 (do not chill longer or dough will discolor).
Preparation Sift flour with salt into a large bowl and blend in butter with your fingertips or a pastry blender until most of mixture resembles coarse meal with small (roughly pea-size) butter lumps. Beat egg with vinegar in a 1-cup measure using a fork, then add enough ice water to measure 1 cup total. Add to flour mixture, stirring with fork until incorporated. Turn out mixture onto a lightly floured surface and knead gently with heel of your hand just enough to bring dough together. Roll out or pat into a 15- by 9-inch rectangle. Arrange dough with short side nearest you, then fold into thirds like a letter to form a roughly 5- by 9-inch rectangle. Chill dough, wrapped in plastic wrap, at least 1 hour and up to 6 (do not chill longer or dough will discolor).