Clean the blue crab and all other ingredients thoroughly.
Pour water into a pot and make broth with kelp and anchovies.
Add blue crab, radish, fish cake, onion, and other ingredients to the broth, and bring to a boil.
Season with soy sauce to taste.
Add green onion, spicy chili peppers, and garlic, then boil further.
Once the fish cakes are cooked, turn off the heat and serve in a bowl.