Before you start, bring a half-full kettle to the boil.
Pat chicken dry and cut into steaks. Place your hand flat on top of chicken and slice through horizontally. Add chicken to a medium pot along with lemon pepper, salt, stock and boiling water measure. Cover with a lid and bring to a boil on medium heat. Once boiling, turn off heat and leave, still covered, for about 15 minutes.
Prep bok choy and place in a large bowl along with remaining slaw ingredients. Toss to combine and season to taste with salt and pepper.
Once chicken is cooked, set aside to rest. Return pot with poaching liquid to high heat and bring to the boil. Add noodles and use a fork to separate the strands. Cover and remove from heat, then leave for 5 minutes. Drain and refresh under cold water. Cut noodles in a few places with kitchen scissors to make them easier to eat.
To finish, roughly shred chicken using two forks, or thinly slice.
Serve noodles topped with slaw, chicken, remaining nuoc cham and peanuts. Season to taste with fish sauce.