Place the chocolate in a bowl set over a small saucepan of gently simmering water, stirring until
melted. Do not let the bowl touch the water. Stir in the coffee. Slowly heat the creams and 100 g of the sugar in a saucepan, stirring until the sugar is dissolved. Bring to the boil.

Meanwhile, whisk the egg yolks and remaining sugar in a bowl using electric beaters until the mixture is thickened and very pale. Very gradually whisk in the hot cream mixture and then return the whole amount to the saucepan. Stir gently over a low heat until the mixture thickens to coat the back of a wooden spoon.

Remove from the heat and stir in the coffee chocolate mixture. Immediately cover the surface of the custard with cling film and cool completely. Chill for 3 hours and then churn in an ice cream maker until frozen. Scoop the ice cream into bowls/teacups and place in the freezer for several hours.

To make the ganache, heat the cream and chocolate together in a saucepan, stirring until melted and evenly combined. Allow the mixture to cool. Pour the mixture into the serving cups to cover the ice cream. Spoon a little of the double cream on each cup and using a cocktail stick, swirl a
pattern over each one.