1. Place the cherries into a bowl and pour on the kirsch. Cover and leave to marinate over night. 2. To make the pastry, cream together the icing sugar and butter until light and smooth. Add the egg yolks one at a time, mixing well and then stir in the water. 3. Add the flour and mix until smooth (this is much easier if you have an electric mixer). Wrap the pastry in cling film in a flat square shape and chill for at least one hour. 4. Set the oven to 180C/gas 4. On a floured surface roll the paste out to a thickness of 3mm and line a 23cm tart tin, leaving a couple of centimetres of pastry over the edge of the ring. Chill again for 20 minutes. 5. Line the pastry case with baking parchment and fill with baking beans. Bake for 25 minutes, and then remove the beans and paper and bake for a further 10 minutes. 6. Remove from the oven and leave to cool. 7. Strain the cherries from the marinade and reserving the Kirsch for later. Scatter the cherries evenly across the cooked tart base. 8. Bring the milk and cream to the boil. Whisk the eggs lightly and pour the boiled milk and cream on to the eggs, stirring well. 9. Pour through a sieve on to the chocolate and whisk well to until the chocolate melts and the mixture is smooth. 10. Fill the tart case and transfer the tart to the oven. Turn the oven off and simply leave the tart to cook in the cooling oven until barely set and the oven is cold. 11. Remove the tart from the oven, and trim off any rough pastry edges with a sharp knife. 12. Place on serving plate and decorate with chocolate shavings. Serve with whipped cream and any left over marinade from the cherries.