Place chicken in a medium bowl. Drizzle with soy and sesame oil. Sprinkle with chilli and sesame seeds. Toss well. Cover and refrigerate for 30 minutes.
Meanwhile, to make pickled vegetables, combine carrot, cucumber and shallots in a large bowl. Add vinegar and sugar. Toss well. Cover and refrigerate for 30 minutes, then drain.
To assemble, use a large serrated knife to cut rolls lengthways down the centre, without cutting all the way. Spread with avocado. Fill with lettuce, chicken, pickled vegetables and herbs. Serve straightaway.

Chicken mixture and pickled vegetables can be prepared several hours ahead. Keep covered in the fridge. Drain vegetables and assemble rolls just before serving.
Shredded, cooked, skinless chicken breast is available from the deli counter in supermarkets. Alternatively, substitute leftover skinless, roast chicken.