Roughly chop the chocolate and melt in a bowl over a warm water bath. Dissolve the coffee in 2 tablespoons of hot water. Cut the vanilla pod lengthwise and scrape out the pulp with the back of a knife
Bring the milk, vanilla pulp and pod to the boil. Remove vanilla pod. Mix sugar and egg yolks. Pour milk over the egg yolks, stirring constantly, then pour everything back into the pot. Stir the mixture constantly and let it slightly thicken at low to medium heat (remove to a rose)
Pour the sauce through a sieve, dividing it between two bowls. Stir the chocolate under one half and the coffee under the other half. Let the masses cool down lukewarm while stirring occasionally. Whip the cream until stiff. Fold about half of it into the chocolate mixture. Chill the rest of the cream. Rinse a box mould (approx. 8 x 22 cm) with water and cover with foil so that the foil extends far over the edge. Pour the chocolate mixture into the box mould, freeze for approx. 30 minutes
Fold the rest of the cream into the coffee mixture and also fill into the box mould. Smooth the surface, cover with protruding foil and allow to freeze for at least 6 hours. Lift the parfait out of the mould, remove from the foil, decorate with grated chocolate and cut into slices. Serve immediately
waiting time approx. 7 hours