Fill a shallow bowl with hot water and soak the rice paper sheets for around 5 minutes until softened. Remove the sheets from the water and place on a clean, dry tea towel. Cut in half.
Blanch the chives in boiling water for 10 seconds, then cool under cold running water.
Take 1 half sheet of rice paper and fill with a little lettuce, spring onions, mint and a crayfish tail. Roll the rice paper sheet to enclose these ingredients, folding in the ends to enclose everything. Tie a chive around the centre of the roll to seal it closed, then place on a tray covered with a clean, damp tea towel while you make the remaining rolls. Serve the crayfish rolls with the hoisin sauce for dipping.