Pie Dough – Makes 1 (9-inch) crust
¾ teaspoon (2.25 grams) kosher salt1½ cups (188 grams) all-purpose flour½ cup (113 grams) cold unsalted butter, cut into ½-inch cubes⅓ cup (80 grams) ice water, plus more as needed
Filling
1¼ cups (250 grams) granulated sugar¼ cup (32 grams) cornstarch5 large egg yolks, (93 grams), room temperature1 large egg (50 grams), room temperature1 tablespoon (5 grams) packed lemon zest⅔ cup (160 grams) fresh lemon juice⅓ cup (80 grams) water1 teaspoon (3 grams) kosher salt5 tablespoons (70 grams) unsalted butter, cubed and softened
Swiss Meringue – Makes about 5 cups
5 large egg whites, (150 grams), room temperature1 cup (200 grams) granulated sugar½ teaspoon (1.5 grams) kosher salt½ teaspoon (1 gram) cream of tartar¾ teaspoon (3 grams) vanilla extract
Pie Dough
In the work bowl of a food processor, pulse flour and salt until combined. Add cold butter, and pulse until mixture is crumbly and butter is pea-size. With processor running, add ⅓ cup (80 grams) ice water in a slow, steady stream just until dough comes together. (Mixture may appear crumbly. It should be moist and hold together when pinched. Add more ice water if needed.)
Turn out dough, and press into a flat disk. Wrap tightly in plastic wrap. Refrigerate for at least 1 hour or up to 2 days. Beyond 2 days, dough can be frozen for up to 3 months. If using dough from frozen, let thaw in refrigerator overnight.
Pie and Filling
Preheat oven to 425°F (220°C).
On a lightly floured surface, roll Pie Dough into a 12-inch circle (about ⅛-inch thickness), rotating dough as needed to prevent sticking. Gently transfer to a 9-inch pie plate, pressing into bottom and up sides, and trim excess dough to ½ inch beyond edge of plate. Fold edges under, and crimp as desired. Dock bottom of dough with a fork, and freeze for 15 minutes.
Top dough with a piece of parchment paper, letting ends extend over edges of plate. Add pie weights.
Bake until edges are golden brown, 15 to 17 minutes. Remove parchment and weights, and bake until bottom of crust is dry and golden, 5 to 7 minutes more. Let cool completely.
In a medium saucepan, whisk together sugar and cornstarch. Add egg yolks and egg, and whisk vigorously until combined. Whisk in lemon zest and juice, ⅓ cup (80 grams) water, and salt until completely combined and no clumps remain. Heat over medium-low heat, whisking constantly, until mixture begins to bubble and thicken, about 7 minutes; cook for 2 minutes. Remove from heat, and strain through a fine-mesh sieve into a heatproof bowl. Add butter, and stir until butter is completely incorporated.
Pour filling into cooled prepared crust. Cover with plastic wrap, pressing wrap directly onto surface of filling to prevent a skin from forming. Refrigerate until completely cooled, at least 1 hour.
Remove plastic wrap from cooled filling; top with Swiss Meringue as desired. Using a handheld kitchen torch, carefully brown meringue as desired. Best served same day.
Swiss Meringue
In the top of a double boiler, whisk together egg whites, sugar, salt, and cream of tartar. Cook over simmering water, stirring occasionally, until sugar dissolves and an instant-read thermometer registers 160°F (170°C), about 7 minutes.
Transfer mixture to the bowl of a stand mixer. Using the whisk attachment, beat at high speed until tripled in volume and stiff peaks form, 3 to 4 minutes. Beat in vanilla. Use immediately.
