Cut napa cabbage into bite-sized pieces. Trim the root of enoki mushrooms and separate them by hand. Thinly slice the lemon. Grate the daikon radish and squeeze out excess water.

Wash the oysters in salted water (not listed in ingredients) and pat them dry.

In a pot, add the soup base ingredients (water, salt, chicken broth powder) and heat over medium heat. Once boiling, add napa cabbage and enoki mushrooms. Cook until softened.

Add the oysters to the pot, cover with a lid, and simmer on low heat for 2–3 minutes until the oysters are cooked through.