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.
*CAUTION
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.