Lemon Meringue Pie

In a medium saucepan combine water, sugar, cornstarch and salt. Bring to a simmer over medium heat, whisking constantly.
When the mixture turns translucent, about 5 minutes, add egg yolks, 2 at a time.
Whisk in lemon zest, lemon juice and butter.
Let mixture come back to a simmer then remove from heat. Cover warm curd with wax paper to prevent a skin from forming on top. Set aside.
Rewarm curd before filling pie shell.

Preheat oven to 375°F.
If you made your own pastry refrigerate the pie shell for 10-15 minutes before baking.
Bake cold pie crust, without filling, until crisp and golden, about 25 minutes. (Make meringue while crust is baking.)
Remove from oven and cool slightly. Add warm filling to warm pastry shell.
Decrease oven to 325°F.

In small saucepan bring water and cornstarch to simmer. Cook, whisking, until thickened, 1-2 minutes. Remove from heat and cool slightly.
In stand mixer beat egg whites, vanilla and cream of tartar on medium speed until frothy, about 1 minute.
Increase speed to medium-high and beat in sugar, a spoonful at a time, until mixture forms soft peaks.
Add cornstarch mixture, a spoonful at a time, and continue beating until glossy with stiff peak, 2-3 minutes.

Reheat lemon curd and pour into warm pie shell. Once pie is full pour leftover lemon filling into small ramekins for a treat later.
Using a spatula spoon meringue onto filling to completely cover. Using the back of a spoon, create nice swirls and peaks in the meringue.
Bake in 325°F oven until meringue is lightly golden, about 20 minutes. Rotate pie halfway through baking time for even baking.
Let pie cool on wire rack until filling is set, about 1½ hours. Transfer to fridge after 45 minutes if you want it to cool down more quickly.