Preheat oven to 375°F. Prepare a 9-inch pie pan.

In a medium mixing bowl, stir together the unbleached flour and sea salt. Using a pastry blender, cut in the shortening until mixture resembles fine crumbs. 

Sprinkle 1 tablespoon of the water over part of the mixture; gently push moistened dough to the side of the bowl. Repeat, using 1 tablespoon of the remaining water at a time, until dough is moistened.

Form dough into a ball.

On a lightly floured surface, flatten the ball of dough with hands. Roll dough from center to the edges, forming a circle about 12 inches in diameter. 

Ease pastry into prepared pie plate, being careful not to stretch the pastry.

Trim the pastry to 1/2 inch beyond the edge of the pie plate. Fold the extra pastry under the edge. Do not prick pastry. Bake with pie filling as directed.

In a large mixing bowl, stir together the pumpkin, sugar, cinnamon, ginger and cloves or allspice. Add egg whites to the mixture until combined. Stir in the evaporated skim milk and water. 

Pour the pumpkin mixture into the pie plate. Cover the edge of pie crust with foil. Place the pastry-lined pie plate on an oven rack.

Bake for 25 minutes. Remove the foil. 

Bake for 25 to 30 minutes more, or until knife inserted near center comes out clean. Cool on a wire rack.

If desired, serve the pie with a whipped dessert topping.

Cover and store pie in refrigerator.