Fill a wide, shallow dish a few centimetres deep with warm water. Working with one rice paper wrap at a time, soak it for a few seconds until it’s flexible, then lay it on a chopping board. Scatter some of the herbs down the centre, then top with a couple of prawns or a little bit of chicken, then some veg pieces and mango, and a small bundle of noodles. Try to keep the fillings in the centre, and don’t overfill. Tuck the ends of the wrap over the ingredients to slightly enclose them, then roll up from the sides, keeping everything as tight as you can. Put the finished rolls on a plate covered with a damp sheet of kitchen paper until you’re finished assembling all the rolls. Will keep in the fridge for up to 24 hrs. Serve with the sesame dipping sauce.