Place cans of milk (unopened) in large pot of boiling water. Water should only be boiling gently. Boil in pot for 4 hours. Remove cans of milk and CAREFULLY open. Pour into pie shell and cool for at least 4 hours. Top with whip cream and serve.
For a Turtle Pie - place chocolate chips in the bottom of the shell before you pour in the milk. For snickers pie, add peanuts and chocolate at bottom of pie shell, add one can of milk (caramel), another layer of chocolate and peanuts then other can of milk.
You can put anything you like in the pie shell - broken heath bars, chocolate chips, toffee chips.... = )