Break up the chocolate ,place it in a small saucepan with 2-3spoon of milk.Heat over a low fire or in a double boiler ,stirring continuosly,not letting it boil (or the chocolate will form lumps),until the chocolate has melted and the mixture is smooth and creamy. Add the rest of the milk,a little at a time,continuing to stir.Remove the pan from the burner and mix the cream and sugar. Allow to cool. Pour the cooled mixture into the ice-cream maker and set the timer for 30 minutes. When the ice cream is well whipped ,remove and serve. Sprinkling it with cocoa,if desired.