In a saucepan, stir together the cornstarch, 2 tablespoons of the sugar, and enough of the hot water to make a smooth paste. Bring to a simmer over low heat and cook, stirring constantly, until thickened and clear. Set aside to cool.
Combine the egg whites and salt in a chilled bowl and beat with an electric mixer on medium speed until soft peaks form. Add the cooled cornstarch mixture, and then the remaining 6 tablespoons sugar, 1 tablespoon at a time, and continue to beat until the whites form stiff peaks but aren’t dry. The meringue is now ready to pile lightly over a pie.
