In small bowl, whisk the cornstarch with 1 cup of water until dissolved. Set aside.

In small saucepan add egg yolks, lemon juice, sugar and the remaining 1 cup of water.

Cook over medium low heat for one minute, stirring constantly. The mixture should not boil but the sugar should dissolve.

When the sugar has dissolved pour in the cornstarch mixture and turn up the heat to medium.

Cook mixture, stirring continuously so that the mixture does not stick.

Cook for 6-8 minutes until it has started to boil, thickens and becomes translucent.

Set filling aside to cool slightly.

Immediately make meringue so filling stays warm.

Whip egg whites on high speed.

Immediately add cream of tartar and whip until soft peaks form.

While whipping, add the sugar one tablespoon at a time to allow it to dissolve.

Add the lemon juice at the end when the meringue is shiny and holds

medium stiff peaks.

Pour the warm filling into the cooled pie shell and spread the meringue on top, making sure to reach the edges of the pastry.

Use your spatula to swirl the meringue into peaks.

Cook the pie at 375ºF for about 6 minutes until meringue is just golden.