Combine pie filling mix, brown sugar, chocolate, and 1/4 cup of the milk in saucepan.
Add egg yolks and blend well.
Then add remaining 1 3/4 cups milk.
Cook and stir over medium heat until mixture comes to a full boil.
Remove from heat.
Blend in butter.
Cool about 5 minutes, stirring once or twice.
Pour into pie shell.
Beat egg whites until foamy throughout.
Add granulated sugar gradually, 2 tablespoons at a time, beating well after each addition.
Then continue beating until meringue stands in stiff peaks.
Pile on filling and spread to edge of pie crust.
Bake in hot oven (425°F.) 5 to 10 minutes, or until delicately browned.