For the crust, stir flour and salt together. Add shortening on top. Cut in shortening with a pastry blender or two knives until the mixture forms pea-sized pieces. Add 3 Tbsp. ice water (ice water prevents the shortening from melting) and work into mixture with a fork, pushing aside the moistened portions.
Sprinkle ice water, 1 Tbsp. at a time on dry areas, and continue working moistened parts to the side until all the dough is moist.
Form dough into a ball. Press dough ball with the palm of your hand to flatten a bit. Roll out on floured surface until about 2? wider than your pie plate. Scrape dough underneath with a metal spatula for a clean release from the counter top. Fold dough in fourths to transfer easily to the pie plate. Align dough so it overhangs by about 2?, then unfold. Trim dough so it hangs over the pie plate by about 1?. If some areas are scant, grab a piece of trimmed dough and use a few dabs of ice water to “glue” it to the area. Fold dough under so a little of it sticks above the pie plate.
Now flute the edges using two of your fingers as support on one hand and your index finger on the other hand to press the dough between your fingers. Be sure to press down so the dough will be right up against the pie plate. This will prevent shrinking. Prick the bottom and edges with a fork so the crust can breathe while baking. Bake at 475 degrees Fahrenheit for 12-14 minutes, or until edges are golden brown. Let cool.
Make the lemon filling while crust is baking. Mix sugar and cornstarch in a 1 1/2 quart saucepan. Stir in water gradually. Cook over medium heat, stirring constantly, until mixture thickens and boils. Boil and stir 1 minute. Stir at least half of the hot mixture gradually into egg yolks. Blend into hot mixture in saucepan. Boil and stir 1 minute. Remove from heat; stir in butter, lemon peel, lemon juice and food color (if desired). Let cool, then pour into pie shell.
For the whipped cream, in the bowl of an electric mixer using the whisk attachment, whip heavy cream with powdered sugar and vanilla extract until peaks form. Spread over lemon layer and refrigerate pies until ready to serve.