To make the dipping sauce, combine all the ingredients in a little bowl.
Soak a rice wrapper in water until pliable, place on a damp tea towel, and neatly arrange the julienned vegetables, avocado, prawns, chives, bok choy, basil and mint leaves, and vermicelli in the centre of the wraps. Use the chilli sparingly.
Fold the bottom of the wrapper upwards, over the fillings, and fold the sides of the wrap over the middle. Then roll up the wrap and slice off the very end of the wrap at an angle. Repeat with the remaining rice paper wraps, and serve with the dipping sauce.