1 tin sweetened condensed milk
Immerse the can unopened in a deep pan of boiling water. Cover and boil for 3 hours making sure that the pan does not boil dry *(see CAUTION).
Remove the tin from the water and allow to cool completely before opening. Inside you will find the soft caramel filling.
It is absolutely vital to top up the pan of boiling water frequently during the cooking of the cans. 2 hours is a long time and if they are allowed to boil dry the cans will explode causing a grave risk to life, limb and kitchen ceilings.