Preheat oven to 350 degrees F (175 degrees C).

Using a fork, poke holds in the bottom of your pie crust then bake for 10 minutes.

In a medium saucepan, combine the sugar, cornstarch, flour, and salt.

Add the lemon zest, lemon juice, water, and egg yolks.

Whisk until well combined.

Place the saucepan over medium heat and cook, stirring constantly, until the filling has thickened.

Pour the filling into the prepared pie crust and set aside.

To make the meringue:

In a large bowl, whisk the egg whites until soft peaks form.

Gradually add the sugar, whisking constantly, until stiff peaks form.

Spread the meringue over the top of the pie, making sure to seal the edges.

Bake in the preheated oven for 12 minutes, or until the meringue is golden brown.

Let the pie cool completely before serving.