Cut zucchini, tofu, onion, potato, green onion, and spicy chili pepper into bite-sized pieces.
Pour water into a pot, add anchovies and kelp to make a broth, then remove them.
Dissolve soybean paste into the broth.
Add potato, onion, and zucchini and bring to a boil.
Add tofu, green onion, and spicy chili pepper and simmer for a while longer.