In a large bowl, cut the shortening and butter pieces into the flour and salt until you have particles the size of small peas. Sprinkle in 4 tablespoons of the water, a little at a time, tossing with a fork until the flour is moistened and the pastry leaves the sides of the bowl. Add 1 to 3 teaspoons more, just a few drops at a time as needed. Gather the pastry into a ball and flatten it; cut it in half and shape it into two disks. Refrigerate for 20 to 30 minutes or overnight.

Roll out one portion of the dough and fit it into a pie plate. Fill the crust following the recipe directions. Top with the second rolled-out portion. Cut slits in the center of the pastry to allow steam to escape. Trim the edge, leaving 1 inch of overhang. Roll the overhang under; seal and flute as desired.

Bake the pie as directed.