Instructions

• In a medium bowl combine 2 ½ cups all-purpose flour and 1 teaspoon salt. Add ¾ cup chilled vegetable shortening and 6 tablespoons chilled unsalted butter cut into cubes. Using a pastry cutter (or two knives or a food processor), cut the shortening and butter into the flour until the mixture resembles coarse crumbs.
• Add 6 tablespoons ice cold water, a tablespoon at a time, mixing with a fork until the dough just holds together when pinched. Do not overwork.
• Divide the dough into two equal portions. Flatten each portion into a disk, wrap individually in plastic wrap, and refrigerate for at least 1 hour (or up to 3 days).
• Preheat the oven to 425°F (220°C).
• Remove one dough disk from the refrigerator. On a lightly floured surface, roll it out to a 13-inch circle. Transfer the rolled dough to a 9-inch pie dish, easing it into the dish without stretching. Leave about 1 inch of overhang (or trim less if you prefer a thinner edge). Return the crust to the refrigerator while you prepare the filling.
• In a medium bowl combine 5 cups fresh blueberries, 1 tablespoon lemon zest, 3 tablespoons lemon juice, ¾ teaspoon ground cinnamon, ½ teaspoon salt, ½ cup white granulated sugar, and ¼ cup cornstarch. Gently toss until the berries are evenly coated and the cornstarch is incorporated.
• Pour the blueberry filling into the prepared bottom crust and spread it evenly. Place the pie in the refrigerator while you roll and cut the top crust.
• Remove the remaining dough disk and roll it out on a lightly floured surface to a 12-inch circle. Use a knife, pastry wheel, or pizza cutter to cut the circle into 10–12 equal strips.
• Arrange the strips over the pie in a lattice pattern: lay half the strips parallel across the pie, fold back every other strip halfway, lay one perpendicular strip across, then unfold the folded strips over it. Continue weaving until the lattice is complete.
• Trim the lattice strips even with the edge of the bottom crust. You can leave about 1 inch of overhang to create a thick rim, or trim more for a thinner crust. Pinch and crimp the edges to seal the top and bottom crusts together.
• In a small bowl beat 1 egg with 1 tablespoon water to make an egg wash. Brush the egg wash over the lattice and the exposed edges.
• Place the pie on a rimmed baking sheet and bake at 425°F (220°C) for 20 minutes. Reduce the oven temperature to 375°F (190°C) and bake for an additional 30 minutes, until the crust is golden and the filling is bubbling.
• Remove the pie from the oven and cool on a wire rack for at least 2 hours before slicing and serving.