Put the carcass in a pot. Add ginger and enough cold water to cover the carcass. Bring to a full boil then cover with a lid. Leave to simmer over low heat for 30 minutes. Pass the broth through a sieve and discard the solid bits.
Cook the noodles
Five minutes before the broth is ready, start cooking the noodles. In another pot, bring plenty of water to a full boil. Add noodles and cook them following the instructions on the package (See note 2).
Assemble the bowls
While waiting, add all the ingredients for the seasonings to each serving bowl. Pour in the broth then add the drained noodles. Place the toppings over the noodles: shredded turkey/chicken, cooked vegetables, preserved mustard stem, and scallions/coriander. Drizzle chili oil over.