Place the flour in a food processor with salt; blitz to combine. Add the butter and blitz until the mixture resembles breadcrumbs. With the motor running, add the egg yolk and the water to form a dough.
Remove dough from processor, wrap in clingfilm and place in the fridge for 30 minutes. Preheat the oven to 160°C.
Roll pastry out onto a floured surface and lightly press into 4 x 10cm tart tins. Return to the fridge for 10 minutes. Cover pastry with baking paper, fill with baking beans or rice and bake for 10 minutes. Remove the beans/rice and paper, and bake the shell for an additional 10 minutes. Remove from oven and allow to cool.
Place the golden syrup and butter in a pot, allow to melt. Add the sugar and stir until the sugar dissolves. Remove from the stove.
Stir the nuts through the hot liquid and pour onto the prepared pastry base. Place on a baking tray and bake for 30 to 40 minutes. Allow to cool before serving.
Makes 4 x 10cm pies