Prepare Baked Pastry Shell; set shell aside.
For filling, in a large bowl, stir to-gether egg yolks and sweetened condensed milk. Stir in lime peel. Gradually stir in lime juice* (mixture will thicken). Pour into the baked pastry shell.
Bake in a 350 degree oven for 30 minutes. Remove from oven; cool completely.
To serve, pipe or dollop the whipped cream or whipped topping over top of the pie, if you like. Makes 10 servings.
If you like, add a few drops of green food coloring to tint the lime filling.
Prepare as above, except substitute 1 to 2 tablespoons finely shredded orange peel for the lime peel and 2/3 cup lemon juice for the lime juice.
In a large bowl, stir together flour and salt. Using a pastry blender, cut in shortening until pieces are peasize. Sprinkle 1 tablespoon cold water over part of the mixture; gently toss with a fork. Push moistened dough to the side of the bowl. Repeat moistening dough, using 1 tablespoon cold water at a time, until all the dough is moistened. Form dough into a ball. On a lightly floured surface, use your hands to slightly flatten dough. Roll dough from center to edge into a circle about 12 inches in diameter. To transfer pastry, wrap it around the rolling pin. Unroll pastry into a 9-inch pie plate. Ease pastry into pie plate, being careful not to stretch pastry. Trim pastry to 1/2 inch beyond edge of pie plate. Fold under extra pastry. Crimp edge as desired. Generously prick bottom and side of pastry in pie plate with a fork. Prick all around where bottom and side meet. Line pastry with a double thickness of foil. Bake in a 450 degree F oven for 8 minutes. Remove foil. Bake for 5 to 6 minutes more or until golden. Cool on a wire rack.