Cut the rice cakes and fish cakes into bite-sized pieces.
Pour water into a pan and add gochujang (Korean red pepper paste), gochugaru (Korean chili flakes), sugar, and soy sauce to make the sauce.
When the sauce starts to boil, add the rice cakes and fish cakes.
Stir and boil until the rice cakes become soft.
Add green onions, boil once more, and it's ready to serve.