Cut the shortening into the flour and salt. Beat the egg, vinegar and water together. Add 1 T of the water mixture over part of the flour mixture. Gently toss with a fork. Push to one side of the bowl. Sprinkle the next T of the water mixture onto the dry part, toss lightly, and push to the side of the bowl. Repeat until all of the water mixture is gone and all of the flour mixture is moistened. Gather with your fingers and form into a ball. Divide into three equal portions. Form each into a ball and flatten slightly. Roll to a 1/8-inch thickness on a lightly floured surface. If the edges split, push them together to seal. Always roll from the center to the edge, using light strokes.
For a pre-baked piecrust, prick the crust with a fork and bake in a preheated 450 Degree F. oven for 10 minutes or until lightly browned.
Emily Griffith Opportunity School As Quoted In The Spotlight Food Section Of The Rocky Mountain News 07-10-94