FOR THE CRUST:
- 1 cup flour
- 1 tsp. salt
- 6 tbsp. chilled butter, cut into pieces
- 2 tbsp. chilled shortening
FOR THE FILLING:
- 1⁄2 cup sugar
- 3 1⁄2 tbsp. cornstarch
- Pinch salt
- 4 eggs, separated
- 3 tbsp. butter
- Juice and grated zest of 2 lemons
- Pinch cream of tartar
- 1⁄2 cup superfine sugar
- 1 cup fresh raspberries (optional)
1. For the crust: Mix together flour and salt in a large bowl. Cut in butter and shortening with a pastry cutter or two knives until mixture resembles coarse crumbs. Sprinkle in 2–3 tbsp. ice water, knead until dough just holds together, wrap, and refrigerate for 1 hour.
2. Preheat oven to 400°. Roll dough into a 12″ round on a floured surface. Ease into a 9″ pie pan. Prick with a fork, cover with foil, and fill with dried beans or pie weights. Bake for 10 minutes. Remove foil and beans. Bake for 10 minutes more. Set aside to cool.
3. For the filling: Reduce heat to 350°. Combine sugar, cornstarch, salt, and 1 1⁄2 cups water in a medium saucepan. Cook, whisking, over medium-low heat for 3 minutes, then remove from heat. Lightly beat egg yolks in a bowl, whisk in 2 tbsp. of the sugar mixture, then whisk into remaining sugar mixture. Simmer, whisking over medium-low heat, for 3 minutes; then add butter and lemon juice and zest.
4. Beat egg whites in a bowl and, when frothy, add cream of tartar. Beat until soft peaks form. Add superfine sugar; beat until stiff. Scatter raspberries (if using) over crust, spoon in lemon filling, then spread meringue on top evenly to edges. Bake until brown, 15–20 minutes. Cool completely.