Submitted by Marcia Karon
I have been making this for decades and happily pass on the recipe to whoever asks. It is sort of a twist on lemon meringue pie.
In a medium size saucepan, mix sugar, cornstarch and salt together, using a wire whisk.
Gradually blend in cold water and crème de menthe until smooth.
Switching to a heat resistant spatula, add beaten egg yolks, blending very thoroughly.
Add margarine. Add boiling water gradually, stirring constantly with spatula. Gradually bring mixture to a full boil, stirring gently and constantly with spatula over medium-high heat.
Reduce heat slightly as mixture begins to thicken and boil slowly for 1 minute. Remove from heat. Stir in chocolate chips. Pour hot filling into baked pastry shell.
Beat egg whites with electric mixer until frothy. Add vanilla and cream of tartar. Beat on high just until whites have lost their foamy appearance. Reduce speed to medium while gradually adding sugar. Return to high speed and beat whites until stiff, glossy and form soft peaks when beaters are removed. Rubbing some meringue between your fingers, you should not feel any sugar granules.
Place meringue on hot filling in mounds. Spread gently to inner edge of crust, sealing well. Cover the rest of the filling by gently spreading meringue. Bake at 350 degrees Fahrenheit for 8 to 10 minutes until golden brown.
Cool on wire rack at room temperature and out of draft for 2 hours.