In a medium bowl mix the egg yolks, cornstarch, and 1/4 cup of the milk (or half-and-half). In a small bowl, mix the gelatin with 2 tablespoons of water and set aside.
Place the remaining milk in a medium saucepan, add the sugar, and cook over medium heat, until starts to simmer.
Remove from heat, and slowly pour 4-6 tablespoons of the hot milk into the egg yolk mixture while stirring.
Run the egg mixture through a sieve over a bowl, then pour it into the remaining milk.
Place the mixture back over the stove, and cook until thickened while stirring.
Remove from heat and add the gelatin and vanilla while stirring until dissolved and distribute.
Pour into a bowl and place a piece of plastic wrap over the surface of the pastry cream. Let cool at room temperature then refrigerate.
Make the meringue: whip the egg white and cream of tartar while you cook the sugar.
Place the sugar and water in a saucepan and cook to 240F (115C).
With the mixer on, slowly drizzle the warm sugar into the meringue.
Beat until stable stuff meringue is formed and it has cooled down to room temperature.
Remove the pastry cream from the refrigerator, then mix in 1/3 cup of the meringue.
Fold in the remaining meringue and use immediately.