Put the milk and chocolate into an earthenware pot and cook over a low heat until the chocolate has melted. Stir constantly so that it does not stick to the pan.
When the chocolate comes to a boil, lower the heat and beat vigorously with a molinillo until a thick foam rises to the top.
Serve hot in earthenware mugs.
c.1998, M.S. Milliken & S. Feniger, all rights reserved