Soak the rice cakes in water for 10 minutes.
Cut the fish cake and green onion into bite-sized pieces.
In a pot, add water, gochujang (Korean chili paste), gochugaru (chili flakes), sugar, soy sauce, and minced garlic. Bring to a boil.
Once the sauce is boiling, add the rice cakes, fish cake, and green onion. Cook for 5–10 minutes.
When the sauce thickens to your liking, turn off the heat.