In a saucepan, combine all the BROTH ingredients (including the mushroom soaking liquid) and bring to a boil. Allow to simmer for 10 minutes.
In a separate pot, boil the noodles according to the package instructions.
To serve, add a portion of noodles to a medium-sized bowl. Top with fish cake slices and chopped scallions. The fish cake is ready to eat and will warm up in the soup.
Ladle broth over the noodles and serve immediately.