1 tin of condensed milk, or Highlander caramel
Traditionally dulce de leche is made by simmering milk and sugar for 4 hours. However, there are two easier options. The first is to cook a whole, unopened tin of condensed milk in a pan of boiling water for 2 hours. The tin must be immersed in water all the time. The other is to use pre-prepared caramelised condensed milk (Highlander caramel).