METHOD:

• Preheat the oven to 325 degrees.  Whisk the sugar, corn starch, and salt together.  Whisk in the water, lemon juice, and zest.  Whisk the egg yolks until no streaks remain and then add to the lemon mixture.  Place the filling mixture in a large pot over medium heat.  Add the butter.  Bring to a simmer, stirring constantly.  Let cook for an additional minute.  Filling should be very thick.  Pour the filling into the warm crust and lay plastic wrap down onto the filling.  Beat egg whites on medium speed until foamy.  Add the cream of tartar and beat until soft peaks form.  Add the sugar very gradually, then beat on high until the peaks are stiff and glossy, but not dry.  Add the vanilla extract and beat for another few seconds.

  Pour the thickened lemon mixture onto the meringue crust. Bake for 10-15 minutes. Cool to cut.