Soak dried shrimps in some hot water till softened, about 15 minutes, rinse, and drain.
Meanwhile, slice pork and add marinade.
Slice napa cabbage, shitake mushrooms, and ginger.
Heat oil in a large saucepan, add ginger, and saute in medium heat till fragrant.
Add dried shrimps and saute till fragrant, then add mushrooms and finally the napa cabbage, saute for 3 minutes.
Add chicken stock and 2 cups water and bring to boil.
Then add the pork, allow soup to return to a boil, reduce heat to medium, cook for 10 minutes, and add salt to taste.
While the soup is cooking, boil 6 cups of water in a large pot. Add the noodles and cook for 5 minutes. Drain and rinse the noodles in cold water, then drain them again.
Add the noodles to the soup and heat for 2 minutes. serve immediately.