Cut the fish cake and green onion into bite-sized pieces.
Pour 300ml of water into a pot and bring to a boil.
Add gochujang, red pepper flakes, sugar, soy sauce, and minced garlic to make the sauce.
Add the rice cakes and fish cake, and simmer over medium heat.
Stir while boiling so the seasoning soaks in evenly.
Add the green onion, bring to a boil once more, and it's ready.