Mix the milk and sugar and boil in a heavy saucepan over low heat.
Stir regularly to prevent sticking. When it has reduced to enough that it becomes very thick (up to 40 mins), remove from the heat and stir until it cools to room temperature.
Serve chilled.
Notes
Dulce de leche a la dominicana is slightly different in texture and flavor to the South American version.To prevent overboiling and sticking you will have to stir constantly once the milk reaches a rolling boil. There will be bits of darker milk as you cook it, as long as it is not burned it is fine, it gives the dulce de leche a bit of a smoky taste.Boil in as big a pot as poosible to prevent overboiling. Another trick is to paint the pot with butter from the rim to an inch below it.Patience. The trick to this is patience. It might take half an hour or more to be done. If when it is cold it is thicker than drinking yogurt add a bit of milk and reheat, mixing in the milk. Remove from the heat as soon as you have incorporated the milk.If it is too runny just boil some more.Yes, this is insanely sweet. This is to be consumed in small portions.