Cut butter into 1/2-inch cubes and freeze. Combine flour and salt in a large mixing bowl; add frozen butter and shortening. Toss together in a food processor and pulse until combined. Pour water through the top until combined. Divide dough in half. Roll out one piece for the bottom crust. Fill with blueberry filling. Roll out second dough. Cut into even strips. Use a ruler to assist with the evenness. Weave into a herringbone design. *See video. Bake in a 350 degree oven for an hour or until browned. Cool on a wire rack.