Lemon Meringue Pie

1½ cups sugar
Pinch of salt
3 Tbs cornstarch
1½ cups cold water
4 egg yolks, lightly beaten
1 grated zest of lemon

½ cup fresh lemon juice
1 Tbs butter
1 9-inch prebaked pie crust
4 egg whites
½ tsp cream of tartar

    
Preheat oven to 350°.
     Filling - in a 2-quart saucepan, stir together 1 cup of sugar, salt, and cornstarch.  Gradually stir in water until smooth.  Add egg yolks, stirring constantly.  Bring to a boil over medium heat and boil for 1 minute.  Remove from heat and stir in the lemon zest, lemon juice, and butter.  Set aside to cool before filling pie crust.
     Meringue - beat egg whites and cream of tartar with an electric mixer until foamy.  Add the remaining ½ cup of sugar 1 Tbs at a time.  Continue beating until stiff peaks form.
     Spread meringue over pie filling and bake for 15 - 20 minutes until the meringue is lightly browned.