In a food processor combine the flour and salt and process for a second to blend. Add the butter and shortening and process, by pulsing the machine, for a few seconds or until the mixture resembles coarse meal.
Add ice water a bit at a time and pulse for a few seconds just until combined. Remove the dough from the processor. Divide the dough into equal two pieces. Flatten each piece into a round flat disk, wrap and refrigerate for an hour.
Lightly flour a pastry board or kitchen counter. Take one piece of pastry out of the refrigerator. Lightly flour your rolling pin. Roll the dough, starting from center of the round, and working up in one direction only, turning the pastry continuously to prevent it from sticking to the counter. Using a 9inch pie plate as guide, roll out your pastry so it is 1/8th-inch thick and about 2 inches wider in circumference than the pie plate. Brush off excess flour and fold pastry circle in half and in half again so that it forms a triangle.
Set point of dough in center of pie plate and unfold it gently. Allow pastry to hang over edges gently. Fill the dough (see below for filling). Roll out second piece of pastry in same manner but after you have folded it in quarters, cut some decorative little vents into it. Reserve, covered.
ROLLING OUT THE DOUGH.
Preheat the oven to 425 degrees.
Set shelf in middle of oven. Peel, core and slice the apples into eighths. Grate the zest and juice the lemon. In a mixing bowl toss the apples with grated lemon zest and juice, sugar, flour, cinnamon and butter. Mound the apples, making them as high as possible in the center. Lay the second round of pastry over the apples, pressing top and bottom crusts together. Trim edges with scissors, leaving a bit of an overhang (about 1/2-inch). Fold the overhang over the top and press together. Crimp the rim with a fork or press with your fingers.
Set pie on a baking sheet and bake for 15 minutes. Lower the heat to 350 degrees and bake for another 35 to 40 minutes or until golden. (Check pie halfway through baking time and protect edging with foil if necessary.)
Remove pie from oven and cool on a wire rack until warm. Serve with wedges of sharp cheddar cheese for dinner (or with vanilla ice cream for dessert).
one double crusted pie, serving 4 to 6.