Heat to almost boiling 1/2 cup butter, 2 cups milk and 1 cup sugar.
Combine 1/4 cup milk and 1/4 cup cornstarch, stir till combine and smooth.
Once butter, milk and sugar are almost to a boil SLOWLY drizzle in milk and cornstarch while continually stirring.
Drizzle and stir. Drizzle and stir.
Once incorporated continuing cooking and stirring till mixture is not quite as thick as pudding.
Pour into a baked pie shell.
Sprinkle with nutmeg.
Bake 10-12 minutes at 350 degrees.
Allow pie to cool and set up before serving.