Combine flour, orange zest, sugar and salt in a mixing bowl; stir
Using pastry blender or two knives, cut shortening into
flour mixture until all resembles coarse meal.
Combine orange juice
with cold water. Add juice-water mixture by tablespoons mixing gently
with a fork just until dough begins to hold together in clumps.
If necessary, an extra tablespoon of water may be added.
dough and shape into a flat, round disk.
Chill at least 1 hour.
Heat oven to 375 degrees F.
On lightly floured wax paper, roll dough to about 1/8-inch thick,
in a large enough circle to overhang pie plate by 1 1/2 to 2 inches.
Ease pastry into pie plate, being careful not to stretch dough,
and fold pastry under at edge. Crimp decoratively. Prick bottom
and sides. Freeze briefly, 15 to 30 minutes.