Combine flour and 1/4 teaspoon salt in a small bowl; cut in shortening with a pastry blender until mixture resembles coarse meal. Sprinkle water over surface of mixture; stir with a fork until dry ingredients are moistened. Shape dough into a ball; cover and chill.
Roll dough to 1/8-inch thickness on a floured surface; trim to a 12- x 10-inch rectangle. Cut pastry into twelve 5- x 2-inch rectangles. Combine cheese, dash of salt, and pepper. Sprinkle 1 teaspoon cheese mixture over surface of each portion, leaving a 1/4-inch margin on all sides. Moisten edges with water; fold over to form a rectangle. Press edges together to seal.
Place on an ungreased baking sheet. Bake at 450° for 12 minutes or until lightly browned. Cool slightly; sprinkle with powdered sugar. Serve warm with soups or stews.