Place the pears in a snug-fitting saucepan and pour over the wine so that they are covered. Add the orange juice, sugar, cloves, bay leaf and nutmeg. Bring the pears up to a simmer and poach them like this until they are utterly tender – a knife rested on the pear flesh should slide in without much prompting. Meanwhile, toast the flaked almonds in a dry frying pan over a medium–high heat, swirling them continuously, until they are golden brown. Leave to cool.
Remove the pears from the liquor and allow them to cool. Remove the cloves and bay leaf from the liquor. Soak the gelatine sheets in a bowl half-filled with cold water for 5 minutes until soft. Lift them out with your fingers and squeeze them over the bowl to remove as much of the water as possible. Whisk the gelatine into the warm wine until melted. Transfer to a jug and set aside to cool (don’t take so long to come back to it that it sets).
Pour the sherry into a wide-based bowl and, taking one biscuit at a time, dunk them so that they soak up the booze but not for so long that they fall apart. Lay them at the bottom of a large glass serving dish. Cut the pears into quarters and remove and discard the cores. Arrange the pears on top of the biscuits.
Now make the custard. Split the vanilla pod lengthways and scrape out the seeds with the back of a knife. Pour the cream and milk into a saucepan and drop in the vanilla seeds and the scraped-out pod. Place over a medium–low heat and bring up to a faint simmer. In the meantime, whisk the egg yolks, sugar and cornflour together until smooth and thick. Tip the hot cream and milk into the eggs and sugar, whisking all the time, then pour the contents back into the saucepan. Remove the vanilla pod. Stir over a low heat, keeping the mixture moving all the time, until it starts to thicken (this will take about 15 minutes); you will know this when faint ribbons start forming behind the spoon. Put the custard in its pan into a basin of cold water to cool; it needs to be thick enough to coat the back of a spoon. Pour it slowly and evenly over the pears. It is imperative that the custard be in one solid layer and go right up to the edge of the bowl so that when the jelly is poured in it does not infiltrate the lower layers. Leave to cool, then put it in the fridge for a couple of hours to set.
Pour the wine jelly very slowly and carefully on to the custard (keeping close to the surface of the custard) and return to the fridge for 4–6 hours, or until set.
Finally, whip the cream with the desired amount of icing sugar to just sweeten it. In good dollops, spoon the cream over the jelly, pulling your hand up at the end of each movement to make nice little peaks. Scatter the toasted almonds over the whipped cream. Finish by grating over lemon zest followed by some dark chocolate, if you desire