1. Place the milk and sugar into a saucepan and heat gently, dissolving the sugar.
2. Place the milk to one side to cool and when cold, stir in the cream and peppermint essence (and the green food colouring if you want to use it).
3. Transfer the complete mixture into an ice cream maker and freeze following the manufacturer's instructions BUT remembering to add the grated chocolate as the ice cream begins to thicken.