Combine flour and salt; cut in shortening with a pastry blender until mixture resembles coarse meal. Stir in mint leaves. Sprinkle water evenly over flour mixture, and stir with a fork until dry ingredients are moistened. Shape dough into a ball, and chill 30 minutes.
Roll dough to 1/8-inch thickness on a floured surface. Line a 9-inch pie plate with pastry. Prick bottom and sides of shell. Bake at 425° for 12 minutes or until lightly browned. Cool completely on a wire rack.