Lemon Meringue Pie
For the lemon curd filling:
1 cup sugar
1/4 cup cornflour
1 cup water
6 large egg yolks
1/2 cup fresh lemon juice
2 tbsp unsalted butter
Whisk the sugar and cornstarch together in a medium sauce-pot, then whisk in the cold water. Have the other ingredients measured and nearby. Bring the sugar mixture up to a full simmer over medium-high heat, whisking as it cooks, until the mixture is thick and glossy.
Pour about a cup of this thickened filling into the egg yolks while whisking, then return this to the pot and whisk just one minute more. Whisk in the lemon juice and cook until the filling just returns to a simmer. Remove the pot from the heat and whisk in the butter then immediately pour the hot filling into the cooled pie shell (the filling will seem very fluid, but it will set up once chilled).
For the meringue:
4 large egg whites, room temperature
1/2 tsp cream of tartar
1/3 cup sugar
3 tbsp sugar
Whip the egg whites with the cream of tartar on medium speed until foamy, then increase the speed to high and gradually pour in the granulated sugar and icing sugar and continue whipping just until the whites hold a medium peak when the beaters are lifted.
Spread the meringue so that it completely covers the lemon filling and connects with the outside crust and create spikes. Bake the pie for about 20 minutes at 325F, until the meringue is nicely browned.
Tip: It is critical that the filling is hot when spread the meringue over. If it cools, the meringue will sweat, creating a liquid layer in between the filling and itself.