Cut fish cakes, onions, and scallions into bite-sized pieces.
Add cooking oil to a pan and stir-fry the onions and scallions.
Add the fish cakes and stir-fry together.
Add gochujang (Korean chili paste), chili powder, sugar, soy sauce, and water.
When the sauce starts to boil, add ramen noodles or udon noodles instead of rice cakes, and cook.
Once all ingredients are well mixed in the sauce, it is ready to serve.