Preheat the oven to 180 C.  Line a 24-25cm tart pan with sweet short pastry.  Cover with baking paper and weights and bake blind for 10 minutes.  Remove the weights and continue to cook until the pastry is a golden biscuit colour and the pastry cooked.
Once the pastry is cooked roast the nuts in a baking dish for 10 minutes or until golden.
At the same time heat the water, glucose syrup and sugar together in a saucepan over a gentle heat, stirring at times with a metal spoons ensuring the sugar is thoroughly dissolved.  Bring the boil and immediately stop stirring. Cook until the mixture reaches 140 C on a sugar thermometer or becomes a rich amber colour.  Immediately stir through the butter, and then the cream, taking care of the mixture spitting.
Continue to cook over a moderate heat, stirring at times until the mixture reaches 120 C.  To test this without a thermometer pour a small amount of syrup onto a saucer with a little cold water.  the caramel should be able to be pushed into a ball that is pliable and not sticky.
Meanwhile pour the nuts into the pastry shell.
Once the caramel has reached 120 C then pour the mixture over the toffee, trying as much as possible to get some on each of the nuts on the surface.
Allow to set for at least 1 hour before cutting into slices and serving.

Can be made 1-2 days in advance and stored in the refrigerator.  Remove 1 hour prior to serving.