Ingredients:
- 1.5 cups (190g) all-purpose flour
- 0.5 tsp fine sea salt
- 0.5 cup (113g) unsalted butter, cubed and ice-cold
- 4 tbsp ice water
- 1 large egg white (for moisture barrier)
- 1.5 cups (300g) granulated sugar
- 6 tbsp (45g) cornstarch
- 1.5 cups (355ml) water
- 0.5 cup (120ml) fresh lemon juice
- 1 tbsp lemon zest, finely grated
- 4 large egg yolks
- 2 tbsp (28g) unsalted butter
- 4 large egg whites, room temperature
- 0.5 tsp cream of tartar
- 0.5 cup (100g) superfine sugar
- 1 tsp cornstarch dissolved in 1 tbsp water
Instructions:
- Combine flour and salt; cut in cold butter until pea-sized crumbs form. Add ice water 1 tablespoon at a time until dough holds. Wrap and chill for 30 minutes.
- Roll out dough and fit into a 9-inch pie dish. Line with parchment and weights. Bake at 375°F (190°C) for 15 minutes.
- Remove weights, brush bottom with egg white, and bake 5 more minutes to seal the crust.
- In a saucepan, whisk sugar, cornstarch, water, lemon juice, and zest. Cook over medium heat, stirring constantly, until thickened and bubbling.
- Temper the egg yolks by slowly whisking in a small amount of the hot lemon mixture, then return all to the pan. Cook for 2 minutes. Stir in 2 tbsp butter.
- Beat 4 egg whites with cream of tartar until soft peaks form. Gradually add superfine sugar and the cornstarch slurry, beating until stiff, glossy peaks form.
- Pour hot filling into the crust. Immediately spread meringue over the filling, sealing the edges to the crust. Bake at 350°F (175°C) for 10-15 minutes until golden brown.
- Cool at room temperature for 1 hour, then refrigerate for at least 3 hours before serving.