Squash and Mushroom Miso Soup

Direction :

Simmer water and kombu:
Combine two quarts water and kombu in a large saucepan; let stand 10 minutes. Bring to a bare simmer (small bubbles slowly emerging at edges of pan) over medium heat, about 15 minutes (do not let boil). Remove kombu and discard.
Add bonito, let stand, then strain:
Add bonito to pan; bring to a boil. Remove from heat and let stand until bonito sinks to bottom of pan, about 10 minutes. Strain, discarding solids (yields 6 cups dashi broth).
Mix miso with some dashi broth; soak wakame:
In a small bowl, whisk miso with 1/4 cup dashi broth to make a slurry. Meanwhile, cover wakame by at least 1 inch cool water, let soak for 10 minutes, and drain.
Simmer remaining dashi with squash and mushrooms:
Return remaining broth to saucepan with squash and mushrooms. Bring to a simmer over medium heat. Simmer until squash is tender but holding its shape, 10 to 13 minutes.
Stir wakame and miso slurry into soup and serve:
Stir rehydrated wakame and miso slurry into pan and simmer until wakame is tender, about 2 minutes. Serve.