Add the vegetable broth and water to a large soup pot. Stir to combine.
Add the green parts of the scallions and the chopped mushrooms.
Bring to a boil and simmer for 5 minutes.
Add the miso and stir to dissolve it. Add the rest of the ingredients and give a good stir. DO NOT BOIL! It will change the flavour and destroy the healthy properties of the soup. If you must heat it do it on low.