Whisk dry ingredients together. With pastry cutter or food processor, mix butter into dry ingredients until coarse meal forms. Mix-in egg just until dough forms. Roll-out dough between two sheets of wax paper, peel off the top, place it back on and peel off the other side. Place in dish and prick with fork. Fill then bake, or bake 30min at 375°F for pre-baked shell.