1. Heat the milk in a medium-sized saucepan.
2. Once the milk is warm, whisk in the chocolate, stirring until melted and steaming hot. For a thick hot chocolate, cook at a very low boil for about 3 minutes, whisking constantly. Be careful and keep an eye on the mixture, as it may boil up a bit during the first moments.
3. Taste, and add brown sugar if desired.
Serve warm in small demitasse or coffee cups.