PIE DOUGH INGREDIENTS:
3 C + 2 T all-purpose flour
3 T sugar
1 t salt
¾ C unsalted butter, cold, cut into small cubes
¼ C all vegetable shortening, cold, cut into small cubes
¾ C ice water
2 T apple cider vinegar
¾ C sugar
4 T + 2 t tapioca flour (basically the same thing as tapioca pearls but ground fine)
3 C fresh nectarines pitted and sliced
2 C fresh blueberries
1 T fresh lemon juice
¼ t freshly grated nutmeg
2 T unsalted butter
Prepare pie dough: Stir together flour, sugar and salt in the bowl of food processor. Add cubed butter and shortening and pulse briefly to combine. Using a quick on-off pulsing action process mixture until shortening and butter are roughly pea-size and well distributed throughout the mixture. The food processor makes short work of the process but you can also do it by hand or with a mixer using the paddle attachment.
Stir water and vinegar together. Add ice cubes to make about 1 ¼ C. Taking care not to add ice cubes, sprinkle about half the liquid over flour mixture. Pulse briefly. Add half of the remaining liquid (minus the ice cubes) and pulse again until a shaggy dough is formed in the bowl of the processor. * You may need to add some of the extra liquid if the dough is too dry.
Turn the dough out onto a lightly floured surface and knead a few times just until dough holds together.
Divide the dough in half and shape each half into a flat disk about 6” in diameter. Wrap in plastic film and refrigerate for at least an hour or for up to three days. (disks may also be frozen at this point for later use)
Prepare Pie: Preheat oven to 425. In a large bowl whisk sugar and tapioca flour together. Add fruit, lemon juice, and grated nutmeg. Toss until well combined and let rest until fruit begins to release its juice.
While fruit rests, remove dough from refrigerator and let stand at room temperature to soften slightly. When softened, roll dough out on a lightly floured surface to a 12” diameter circle. Transfer to a 9” pie plate, pressing bottom and up sides. Trim dough to a 1” overhang. Fill with fruit mixture and dot with small pieces of butter.
Roll out the remaining disk to cover top of pie decoratively and crimp edges. Freeze pie for 20 minutes. Chef’s Tip: This step is not required, but I think it helps reduce pie crust shrinkage and slump in oven. Remove from freezer and place on rimmed, parchment lined baking sheet. Brush top of pie with beaten egg and sprinkle with coarse sugar.
Bake for 10 minutes at 425 and then reduce oven temperature to 375. Continue to bake until filling has thickened and is bubbly. 45-50 minutes. Let cool for 2 hours before serving.