To make the dough: In a large bowl, stir together the flour and salt. Add the butter and toss to coat with the flour, then flatten the bits of butter between your fingertips. Add the vegetable shortening, toss to coat with the flour mixture, and then flatten into pieces a little bigger than the butter. (Using just the tips of your fingers helps produce a flaky crust.)

Divide the dough into 2 balls, flatten into disks, and wrap well in plastic. Refrigerate for at least 2 hours, or overnight. The dough can be frozen for up to a month; thaw overnight in the refrigerator.

To make the filling: In a large bowl, whisk together the sugar, cornstarch, cinnamon and salt.

On a lightly floured surface, roll one disk of dough into a 13-inch circle, then fit it into a 9-inch pie dish. Roll the other disk into a 13-inch circle.

Add the apples to the sugar mixture and toss thoroughly. (We combine the apples with the sugar at the last minute so the mixture stays drier and doesn’t weigh down the dough.) Pour the apple mixture into the dish. We call for just the right amount of apples. Don’t be afraid if you see them piled high. Cover with the remaining dough circle, then trim the excess dough and crimp the edges.

Cut about a dozen slits all over the pie. Sprinkle liberally with sugar and cinnamon, and place on a baking sheet lined with aluminum foil. (This way you needn’t worry about any juices that may bubble over.) Bake until the crust is golden and the filling is bubbly, 65 to 75 minutes. Transfer the pie to a rack and serve warm, or at room temperature.