For the pastry:
Boil the butter and honey together. Cut the pastry into strips at the widest part of the sheet. Take a strip of pastry and brush with the honey butter, layer another on top and brush again. Wrap around a tart ring or case and bake in a hot oven at 180˚C for 8 - 10 mins until golden brown.
Caramelised pears:
Peel and chop the pears into cubes. In a saucepan heat the caster sugar until it begins to turn an amber coloured caramel. Add the butter, juice, cream, salt and vanilla to make a butterscotch style sauce, bring to the boil and add the pears. Bring the heat up again, stirring occasionally until the pears are coated in caramel and remove from the heat.
Elderflower custard:
In a saucepan heat the milk and cream with the elderflower until just below boiling. In a bowl whisk the eggs and sugar and cornflour. Pour the hot cream mixture on top whisking continuously. Pass the custard mix through a sieve into a saucepan and return to the heat stirring the mixture until it begins to thicken. Leave to cool.
Pear and elderflower granite:
Pour the 2 liquids into a lunchbox style container and freeze solid.
To serve:
Place the tart cases on a plate and cover the bottom with the warm pears.
Spoon the elderflower custard over the top. Remove the granita from the freezer and scrape with a fork. Cover the tart and serve.