Step 1 Chop the chocolate fine. Heat the milk and cream to boiling in a saucepan, then remove the pan from the heat. Add the chopped chocolate. Stir well until dissolved. Let the mixture steep 10 minutes.
Step 2 Whisk the egg yolks to a thick ribbon. Return the cream-chocolate mixture to barely a simmer, then pour over the egg yolks while whisking constantly. Strain the custard and cool.
Step 3Place in an ice cream maker and freeze according to the manufacturer's instructions. Chill in the freezer 4 hours before serving.
Step 4To serve, scoop the ice cream into a mug. Pour the chocolate sauce over it and top with the chopped almonds and a cinnamon stick. (Makes 1 1/2 quarts ice cream.)