Prepare the noodles as per packaging instructions (either soak in hot water or boil briefly) then drain and rinse under cold water. Drain thoroughly before combining with the other ingredients.
To prepare the pomelo start by cutting off the slightly more pointy end and scoring the rind several times all the way around. Peel then separate individual segments. Remove the membranes as well and use only the pulp. Crumble the pulp and assemble the salad.
Make the dressing by combining the ingredients and stirring until smooth.
Place the noodles on a large plate (or in a bowl) and crumble the pomelo over the top. Add the avocado and herbs, scatter the nuts and chopped chili pepper (if using), drizzle over the dressing and serve.
When you are shopping for pomelos make sure they are heavy (this means they will be juicy and delicious) and have a firm rind.
Depending on the type of pomelo you use you might be able to prepare it in advance (if it holds its shape exceptionally well) and refrigerate it, covered, for a few hours.
You can make the dressing ahead and refrigerate it, covered, for up to 2 days. Stir before drizzling over the salad.
I recommend using either been thread noodles (or similar) or rice noodles in this pomelo salad. Wheat noodles might be a little overpowering.
Rinse the noodles under cold water and drain well before assembling the salad. You may want to chop the noodles roughly before making the salad (easier to combine with the other ingredients).
You shouldn't need to add any seasoning to this salad as the sweet-and-savoury dressing has lots of depth of flavour.