Instructions

1. If using fresh clams, place them in a 3.5% salt solution and let them sit in a dark place for 2–4 hours to purge any sand. Rinse thoroughly under running water. If using frozen clams, follow the package instructions.
   
2. Warm the dashi broth over low heat.
   
3. While the broth is heating, thinly slice the green onion.
   
4. Add the clams to the hot broth and cook gently over low heat, avoiding a full boil. Skim off any foam that forms on the surface. Once the clams open, remove the pot from the heat. Discard any clams that remain closed.
   
5. Scoop out a small amount of the hot broth and dissolve the miso paste in it using a small whisk or spoon. Return the mixture to the pot and stir gently to combine.
   
6. Serve the soup hot, topped with sliced green onion.