put the chocolate in a double boiler over barely simmering water. Stir occasionally until melted. Remove from heat and let cool slightly.
Place the sugar and water in a pan over medium heat and stir until the sugar has dissolved. Stir in the chocolate. Remove from the heat. Let cool to room temperature. Chill in the refrigerator for 30 minutes. Place the mixture in an ice cream machine and proceed according to the manufacturer's instructions.
If you don't have an ice cream machine, place the chocolate syrup in a metal bowl and freeze. When the mixture has just begun to set whisk it with electric beater or by hand, until creamy. Repeat at least three or four more times or until sorbet is thick and smooth. Serves four