Gluten Free Pie Crust

Preheat oven to 350 degrees F. Sift together rice and tapioca flour, potato and cornstarch, sugar, baking powder, xanthan gum, and salt into a mixing bowl. Cut cold shortening or butter into dry ingredient. Blend with a pastry cutter until butter in incorporated into eh dry ingredients. The dough should hold together when squeezed. Beat egg with vinegar and mix into dough. Form dough into a ball with your hands. Add a little tapioca flour if the dough is too sticky. Roll out the dough between to sheets of wax paper. The dough should be about 1 1/2 inches larger in diameter than the pie plate. Peel one sheet of wax paper away from dough. Place pie curst in pan. Remove top sheet of wax paper. Trim excess dough and crimp edges to form a decorative border. TIP: If the recipe calls for a baked pie shell, prick the dough with a fork and bake at 350 degrees F. for 10 to 12 minutes. Cool before filling.