1.Chop 150g (4½ ounces) of the chocolate; shave remaining chocolate with a vegetable peeler to make small curls.
2.Heat milk, cream and halved cinnamon stick in a medium saucepan; simmer gently, uncovered, without boiling, 5 minutes. Whisk in chopped chocolate, vanilla, sugar and salt until chocolate is melted. Remove from heat; discard cinnamon. Stir in liqueur. Adjust sweetness to taste.
3.Pour hot chocolate mixture into heatproof mugs; sprinkle with chocolate curls.
We used crème de menthe for the mint-flavoured liqueur.Note