Sift the flour and salt into a medium bowl. Add the shortening. Using a pastry blender or two knives (drawing them apart in a crisscross pattern), cut the shortening into the flour until the mixture resembles coarse crumbs with a few pea-sized bits.
Stirring with a fork, gradually add enough of the water for the mixture to clump together (you may not need all of the water). When you press the dough together, it should be moist and malleable, without cracking, so add a bit more water if need be. Gather up the dough and press it into a thick disk. Wrap in plastic wrap or waxed paper and refrigerate for 30 minutes to 1 hour. The dough is easiest to roll out if it is chilled but not hard. (The dough can be refrigerated for up to 1 day. If the dough is chilled until it is very firm, let it stand at room temperature for about 10 minutes to soften slightly before rolling it out.)
Freeze a medium bowl until it is chilled, about 5 minutes. Add the cream, confectioners’ sugar, and vanilla. Whip with an electric mixer on high speed until the cream forms soft peaks. (The cream can be covered and refrigerated for up to 1 day. If it separates, whisk until thickened.)
Unwrap the dough and place it on a lightly floured work surface. Sprinkle some flour over the top of the dough. Roll out the dough into a 12- to 13-inch round about 1/8 inch thick. Fit into a 9-inch pie pan. Trim the excess dough to make a 1/2-inch overhang around the edge of the pan. Fold the dough over so the edge of the fold is flush with the edge of the pan. Flute the edge of the dough. Pierce the bottom of the dough about a dozen times with a fork. Freeze the dough for 20 to 30 minutes.
Position a rack in the bottom third of the oven and preheat the oven to 375°F. Line the inside of the piecrust with aluminum foil. Fill the foil with pie weights, dried beans, or uncooked rice. Place the pan on a rimmed baking sheet.
Bake until the exposed dough looks set and is beginning to brown, 12 to 15 minutes. Lift up and remove the foil with the weights. Continue baking the piecrust until it looks dry on the bottom, about 10 minutes more. (If the piecrust puffs, pierce the crust with a fork.) Transfer to a wire cake rack.
Meanwhile, make the filling: Pierce each sweet potato a few times with the tines of a fork. Place them, in a spoke pattern, on the turntable of a microwave oven. Cook on high (100%), turning the sweet potatoes over after 4 minutes, until they are tender, 8 to 10 minutes total. Let cool for a few minutes.
If necessary, return the oven temperature to 375°F. Using a kitchen towel to protect your hands, split each sweet potato and use a spoon to scrape the flesh into a medium bowl. Mash the sweet potatoes—you should have about 2 cups. Using an electric mixer set on medium speed, beat in the melted butter. Add the sugar, evaporated milk, eggs, nutmeg, cinnamon, and salt and beat on low speed just until the sugar is dissolved. Spread the filling evenly in the pie shell. Place the pie on a baking sheet.
Bake for 15 minutes. Reduce the oven temperature to 350°F. Continue baking until the filling is set and doesn’t jiggle when the pie is gently shaken, about 30 minutes more. Transfer the pie to the wire rack and let cool completely. (The pie can be covered with plastic wrap and refrigerated for up to 1 day. Let stand at room temperature for 1 hour before serving.)
Slice the pie and top each serving with a dollop of whipped cream.
Patti’s Pointers: Why evaporated milk? Even if a farmhouse didn’t have a refrigerator, country folks usually had canned evaporated milk in the kitchen cupboard. This ingredient is rich and sweet because the excess water has been removed (evaporated) before canning.
(Excerpted from the Desserts LaBelle by Patti LaBelle. Copyright © 2017 by Pattonium Inc.)