You will need a 10in tart tin, preferably 1 1/2in deep, with a removable base; some baking parchment; dried baking beans.
Preheat the oevn to gas mark 5, 375øF, 190øC.
Put the flour, salt, sugar in the processor and whiz for a few seconds. Chop the butter roughly with a knife, add to the flour, and process for about 15 seconds until you have a rough, crumb-like mixture. In a small bowl, whisk the egg yolk and water together and then add to the flour and butter. Whiz for about 30 seconds or until the pastry dough has left the sides of the bowl and is clinging in a solid mass around the central spindle. Take out the pastry and lightly mould with your hands into a flattish round, so that later it will roll out more easily to the shape of the tart tin. Wrap it in clingfilm and put in the fridge to rest for about 30 minutes or overnight.
Take a scrap of butter and thoroughly grease the tart tin, paying special attention to the area where the base and sides meet. Roll out your pastry to the thickness of a chamois leather (you will have some surplus). Line the tart tin, making sure you do not strtch the pastry, by starting in the middle of the tin and draping the pastry gently and easily outwards towards the corners and then up the sides. Prick the base all over with a fork and put the tin back into the fridge for another 30 minutes.
Meanwhile, cut a piece of baking parchment to fit inside the pastry crust. Remove the pastry lined tin from the fridge, line with the baking parchment and sprinkle some beans over the bottom. Place in the preheated oven and bake for 15 minutes until the pastry has 'set' and is light golden. Remove from the oven, take out the parchment and beans, and return pastry crust to the oven for a further 3 minutes to colour the bottom. Then remove again and leave to cool, still in the tin.
Put the biscuits in a food processor and whiz until coarse crumbs. Empty and combine the crumbs and ground hazelnuts in a bowl. Now put the butter and sugar in the food processor and cream together until smooth and fluffy. Beat the eggs in a small bowl until well mixed. To prevent the 'frangipane' curdling, first add about a third of the nut and crumb mixture to the creamed butter in the food processor and whiz for a few seconds until incorporated. Carry on with the nut and crumbs, then egg, until everything is mixed in but do not over process. Finally, add the ginger wine or other liqueur.
Peel the pears and cut them in half lengthways. Core, but leave the stalks on. Then make lengthways cuts down the pears, as if to fan, leaving the base intact. Now spoon in the frangipane mixture to cover the pastry case and place the pears on top with the stalks pointing towards the middle. Bake for 25 minutes at gas mark 3, 325øF, 170øC until golden brown and the mixture only just set - it's better if the mixture is still a little soft in the centre as it add a creamy texture to the finished tart. This is better eaten just warm rather than piping hot. Serve either plain or with a good dollop of creme fraiche.