Strip the remaining meat from the roast chicken carcass and refrigerate.
Simmer 2 l of water in a large saucepan.
Add chicken carcass, juices, carrots, leeks, onion, bay leaf, peppercorns, and stock cube to the water.
Boil the stock, then simmer for one hour while skimming off any surface scum.
Strain the stock through a colander into a fresh pan and discard solids from the carcass.
Bring the strained stock back to a simmer on the heat.
Tear the reserved chicken meat into bite-sized pieces.
Add noodles for one minute, then add chicken, bok choi, onions, corn, soy sauce, and coriander.
Cook for 3 minutes and serve among four bowls.