The first time I had the brilliant idea to make dulce de leche from scratch (what we call manjarblanco), I chose the easiest recipe I could find: cooking a can of condensed milk for a couple hours in boiling water. Almost magically, the heat of the flame transformed the milk inside into a golden, caramelized cream of perfect consistency and taste. It’s obvious to me now, that the can needs to be completely cool before opening it, but back then, I was new in the kitchen and too impatient to sit down and wait.