Cut zucchini, onion, potato, tofu, and green onion into bite-sized pieces.
In a pot, add anchovies and kelp with water to make a broth. Remove the solids after boiling.
Dissolve doenjang (soybean paste) in the broth and bring to a boil.
Add potatoes, zucchini, and onion, and continue to boil.
Add tofu and green onion and let it simmer one more time.