Put the sugar in a saucepan with 250ml water and simmer over medium heat until the sugar has dissolved. Add the chillies (green tops attached) and simmer for 15 to 20 minutes. Remove the chillies and reserve one tablespoon of the poaching syrup.
Place the milk, cream and chopped chocolate in a saucepan and heat over low heat until the chocolate has melted, whisking all the time.
Finely chop one of the candied chillies and add with the reserved syrup. Add a little to start, then more if you want a more fiery flavour. Serve with extra chillies if you wish.