Prepare the rough puff pastry, add the flour and salt to the bowl of a food processor, pulse to mix.
Cut the cold Stork block into 1/2cm slices and add to the food processor bowl. Using the pulse function process until the Stork is broken up but still in visible lumps. Tip the mixture out into a large mixing bowl. Make a well in the centre and add the juice of half a lemon and then enough cold water to make a dough. Use the blade of a table knife to mix the dough rather than your hands.
Gather the dough into a ball, wrap in cling film and chill in the fridge for 1 hour to firm.
Take the chilled dough out of the fridge, lightly flour the work surface. Roll out the dough into a long upright rectangle shape.
Fold into three like an envelope top down first, then bottom up.
Turn the dough 90 degrees to the right so that the folds are now left and right. Roll out again to a large rectangle and fold into three again. Turn and then repeat this step twice more, turning before each re-rolling and folding.
Each roll and turn the pastry gets smoother and more refined. Wrap again in cling film and allow it to chill for another hour in the fridge before using.
Peel the pears, leaving the stalk intact. Slice the base from the pear giving a flat bottom for the pear to sit on.
In a large pan place the blackberries, vanilla, water and caster sugar. Heat gently until the sugar melts. Bring the pan to a simmer and carefully add the pears.
Cut a circle of baking paper to fit the top of the pan and cut a circle from the middle. Set this paper disc onto the contents of the pan. Allow to simmer for 20-25 minutes until the pears are tender.
Remove the pears from the pan with a slotted spoon and stand on a plate. Allowing to cool to room temperature.
With a slotted spoon remove the blackberries from the pan and push through a sieve to puree and remove the seeds.
Add the puree to a smaller pan along with 500ml of the liquid. Place on the heat and simmer until reduced by half and thick and syrupy. Set to one side to serve with the pears.
Take the block of rough puff pastry from the fridge and cut in half.
Roll out one portion of the pastry, on a lightly floured work surface, to create a rectangle roughly 40cm x 20cm.
Using a sharp knife or rotary pizza cutter divide the rolled out pastry into strips approx. 1.5cm wide.
Roll each strip up into a wheel. This makes it easier to wrap around the pears.
Line a baking tray with non-stick baking paper and preheat the oven to 200c (fan)/220c/Gas Mark 7.
Take one cooled poached pear at a time and starting at the top by the stalk begin to wrap a pastry strip around the pear, overlapping the pastry slightly. As you reach the end of the first strip of pastry take a new strip and tuck the end underneath the last strip and continue wrapping the pear until you reach the base. Secure the end of the pastry strip by tucking in under the base of the pear.
Set onto the lined baking tray and repeat wrapping each pear.
Brush each with egg wash and sprinkle with a little caster sugar.
Bake in the oven for 20 minutes until golden.
Serve with the reserved blackberry sauce and fresh blackberries.