In a large bowl, add flour, shortening and salt. Using a pastry cutter, cut the shortening into the flour until it resembles small pea size pieces.
In a 1 cup measuring cup, add the egg and beat until it's a light lemon color.
Add the vinegar, and water, stir well
Add the egg mixture to the flour mixture, stir together until well blended. You may have to work it with your hands to mix the ingredients, but don't knead it, or overwork it; mix just until blended.
Divide the dough into two equal pieces. Using one piece of dough, place the dough on a solid surface. Sprinkle a little flour on top, and using a Rolling Pin, roll out the dough, sprinkling a little more flour if needed, until it's big enough to fit in the pie plate, and hang over the edge a little. Gently press the dough into the pie plate, and pinch the edges, and trim any remaining dough. Set aside.