To a large pan, add the dried anchovies, dried kelp, and onion along with 5 cups of water. Bring it to a boil over medium high heat. Reduce it close to medium if your heat is very high.
Add the rice cakes. Boil until the rice cakes become very soft and the sauce is thickened. This can take longer, depending on your rice cakes. Stir frequently.
Drop the vegetables, garlic, and fish cakes in. Continue to boil. Depending on rice cakes, you may need more time to reach a desired level of softness. Drop in the scallions and boiled eggs.