Moisten the coffee grounds with a little water and put onto a muslin square with the cardamom pods and cinnamon stick, then tie securely with kitchen string to make a bag. Put the cream into a heavy based saucepan with the muslin bag and bring to the boil, then lower the heat and simmer for 5 minutes. Turn off the heat and leave to cool and infuse for about an hour.

Squeeze the muslin bag back into the pan to extract as much flavor as possible, then discard it. Reheat the infused milk gently, thin add the grated chocolate and stir until it has melted.

In a separate bowl, whisk the egg yolks with the sugar. Pour on the hot cream mixture and whisk gently to combine. Pour the mixture back into the rinsed out pan and cook gently until it thickens to a custard consistency. You should be able to draw a distinct line through the custard on the back of a spoon. Remove from the heat immediately and cool in a sink of ice water. Stir from time, to time as the mixture cools down.

Spoon the coffee cream into ramekins or little glasses and chill before serving.