Cut the rice cakes into bite-sized pieces.
Cut the fish cakes into bite-sized pieces.
Add water, gochujang (Korean chili paste), red pepper powder, and sugar to a pot and bring to a boil.
Once the water is boiling, add the rice cakes and fish cakes.
Stir and simmer for about 10 minutes so the seasoning soaks in well.
Slice and add the green onion, then it's ready to serve.