Prepare the rice noodles as per the instructions on the packet. (Usually by soaking in boiling water for a few minutes then rinsing.) Once cooled, chop roughly.
Chop everything - the prawns, lettuce, carrots, spring onions, chillies and herbs.
Juice the two limes.
Put the fish sauce into a bowl and add the sugar and rice vinegar. Stir well until the sugar has dissolved.
Add the chopped chillies, one third of the spring onions, the garlic and about 4-5 tbsp each of the chopped coriander and mint.
Mix well again and set aside.
Put the chopped noodles in a large bowl. Add the prawns, lettuce and the remaining spring onion and mix well.
Add about 4tbsp each of the chopped basil, mint and coriander. Next, add the lime juice and 2 tbsp of the dipping sauce. Mix well again.
To finish the rolls you'll need to rehydrate the rice paper. Again this varies depending on the brand so check the instructions on the packet. Usually it'll involved soaking in either warm or cold water for a minute or two. One prepare one rice paper at a time! Ensure the work surface that you plan to make the roll on is also wet to avoid it sticking.
Place a spoon or two of the filling on the wrap, just off centre. Start rolling then close in the ends and finish rolling. Once the paper dries a little it will hold.
How much rice paper do you need? This depends on what you're making! If you use small pieces of rice paper you'll need 20 - 30 sheets to use all the mixture. These are ideal as appetisers. If you would prefer something a bit more substantial use larger pieces of rice paper - you'll probably need 10 - 12 sheets.