Remove the meat from the chicken thighs, reserving the bones, and slice it into nice thin strips. Place a large pan over a medium–low heat with a good lug of oil, then fry the shallots, ginger and garlic for 5 minutes, or until soft. Add the chicken and some sesame oil and fry for a few minutes more. Throw in the chicken bones and star anise, then cover with 700ml of water. Gently bring to the boil, reduce the heat to low, then cover and simmer for 35 to 40 minutes, or until the chicken is tender. Season the broth with the soy sauce and black pepper. Fish out and discard the bones.
Meanwhile, cook the noodles according to the packet instructions, then divide between two deep bowls. Pick the herbs, chop the tofu into 1cm cubes, trim and finely slice the spring onions, then finely slice the chilli. Ladle the broth over the noodles, then top with the herbs, spring onions, chilli, spinach and tofu. Roughly chop and scatter over the nori, then finish with a squeeze of lime.