Cut the onion, zucchini, potato, and tofu into bite-sized pieces.
Put kelp and anchovies in a pot to make broth.
Dissolve doenjang (soybean paste) in the broth and bring to a boil.
Add the prepared vegetables and cook until tender.
Add tofu, chili peppers, and garlic.
Taste and season with salt if needed.
When the flavors have blended into the broth, it's ready to serve.