Preheat oven to 200°C (180°C fan-forced). Line a baking tray with baking paper.
Cut six 10cm rounds (or squares) from pastry and place on prepared baking tray. Using an 8cm cutter score part-way through pastry to form a 1cm border, dock (prick) the centre circle with a fork and brush all over with egg yolk. Place in freezer for 10 minutes or until firm.
Bake in preheated for 10 minutes, until puffed and pale golden.
Remove from oven, using a small serrated knife cut centre top layers of pastry and discard.
Return vol-au-vents to oven and bake for a further 10 minutes or until dark golden.
Remove from oven, place on wire rack and allow to cool.
Meanwhile, in a small mixing bowl combine mayonnaise, wasabi, zest and juice together, mixing until well combined. Set aside until required.
To serve, add the prawns to the mayonnaise mixture, stirring until well coated. Spoon six prawns into each vol-au-vaunt, top with pink ginger and garnish with snow pea shoots.