Prepare pie dough the night before to chill in the refrigerator for at least 2 hours before rolling out and blind baking.

Preheat oven to 375°F (190°C) and adjust oven rack to the lowest position. Partially blind bake pie crust in a 9-inch pie dish.

Reduce oven temperature to 350°F (177°C).

Whisk the egg yolks together in a medium bowl and set aside.

In a saucepan over medium heat, whisk together water, sugar, cornstarch, salt, lemon juice, and lemon zest. Cook until thick and bubbling, about 6 minutes.

Slowly stream a few spoonfuls of warm lemon mixture into the beaten egg yolks, then whisk the egg yolk mixture back into the saucepan. Cook until thick and big bubbles burst at the surface, then whisk in butter.

Spread the filling into the warm partially baked crust.

Beat egg whites and cream of tartar on medium speed for 1 minute, then on high speed until soft peaks form, about 4 minutes.

Add sugar and salt, then continue beating until glossy stiff peaks form, another 2 minutes. Spread meringue over the filling, touching the edges of the crust.

Bake on the lowest oven rack for 20-25 minutes. If browning too quickly, tent with foil. Remove and cool at room temperature for 1 hour, then refrigerate for 4 hours before slicing.