Rinse the tilapia fillets thoroughly and cut them into bite-sized pieces.
Slice the radish, onion, green onion, spicy green chili pepper, and tofu into appropriate sizes.
Bring water and kelp to a boil in a pot to make broth.
Add the radish and onion to the broth and boil.
When the radish is cooked, add the tilapia fillets, chili peppers, and tofu.
Season with red chili powder, soybean paste, minced garlic, soup soy sauce, and salt.
Once all ingredients are cooked, add the green onions and simmer a little longer.