Pour the milk into a large pan, and bring almost to the boil over a medium heat.
Meanwhile, add all the chocolate mix ingredients to a large jar, finely grating in the chocolate, then give it a good shake to combine.
You need around 10 heaped tablespoons of the chocolate mix for this amount of milk. Simply spoon the chocolate mix into the hot milk, give it a good whisk and leave to bubble away for a few minutes before serving – you’re looking for that gorgeous, thick, almost claggy, knockout texture.