Separate the egg yolks from the egg whites, putting the yolks in a medium bowl. Set the egg whites aside in a large bowl.
Mix in with the egg yolks: 1 cup of sugar, 1/4 heaping cup of flour, cocoa powder, and 1/2 cup of milk. Set this mixture aside.
In a medium saucepan, cook 1 1/2 cups of milk over medium heat until bubbles form around the edge.
Add the hot milk to egg yolk mixture, stirring constantly as you add the hot milk.
Pour the hot mixture back into the medium saucepan, and cook over medium heat until the mixture turns thick.
Add the chocolate mixture to the pre-baked pie crust.
To make the meringue, beat 1/2 cup of sugar, egg whites, and cream of tartar until stiff peaks.
Spread meringue on top of chocolate mixture, sealing the meringue around the edges of the crust.
Bake at 400 degrees for 4 to 5 minuts, or until merinuge is starting to browned on top.
Cool on a wire rack, and serve at room temperature.
Store in the refrigerator for up to four days.