This is my husband's favourite dessert. It makes the best use of local ingredients in Piemonte and Valle d'Aosta in the autumn and winter: pears and chestnuts. The combination with the chocolate, also another local speciality, is utterly decadent. The pastry and pears can be made 1 to 2 days in advance. If you are short on time, you could use store bought short crust pastry and tinned pear halves. The only thing you will need to make is the chocolate custard filling.