In a stockpot, bring water to boil, then add chicken bones. Simmer the liquid, do not hard boil, and skim any excess if any.
Use a sachet or coffee filters to combine cilantro stems & shitake stems; black peppercorn & coriander seed; star anise & cinnamon sticks. By doing this, you'll save a lot of time to take them out when the broth is done cooking.
Once the liquid is simmer with the chicken bones inside, add the rest of ingredients (including the ones in sachets). Bring to soft boil and let it simmer for 1.5 hours. By this point, the fragrance from soup stock has released and you can smell them through the entire house.
After 1.5 hours, take out the bones and all the infused ingredients out. If you don't put small ingredients in sachets, you must strain the broth in order to have a clear consistency.
In a small mixing bowl, combine all seasoning ingredients. Put about 2 cup of the hot soup broth into the bowl, stir well to dissolve all the seasoning. Then pour it in the soup pot. Please handle it carefully to avoid getting burn.
Taste the broth and adjust it according to your own taste. If you want more saltiness, add soy sauce first then followed by seasoning powder. If you want less salty, add sugar and a little bit of oyster sauce.
In a cooking pan, cook shitake caps by soft boiling them or searing on very low heat with no oil. For the egg noodle, choy sum and bok choy, you can fast boil them right before serving.
Assemble: In a big bowl, put in a desired amount of egg noodle, then come roasted duck, shitake, bok choy or choy sum. Ladle soup broth cover the entire noodle bowl. Enjoy!