1 small package bonito flakes (5g)
4 cups water
1 sheet nori, torn into small pieces
3 tbsp white miso
3 green onions
8 mushrooms, sliced thin

Bring bonito flakes and water for a boil for 5 minutes. Add in nori and let sit off the heat for 15 minutes. Strain the solids out and discard. Take the broth and put back into the pan. Add in the miso, onions and mushrooms. Let simmer until you are ready to serve.

Tofu would also make a great addition to this soup.