Cut tofu, zucchini, potato, onion, and other ingredients into bite-sized pieces.
Pour water into a pot and make broth with anchovies and kelp.
Dissolve doenjang (soybean paste) in the broth, then add potatoes, onion, and zucchini and bring to a boil.
Add tofu, spicy chili peppers, and green onions, and continue boiling.
Once all ingredients are cooked, season with salt and pepper to taste.