Cut fish cakes into bite-sized pieces.
Slice onion, carrot, and green onion into thin strips.
Heat cooking oil in a pan and sauté the onion and carrot.
Add the fish cakes and stir-fry together.
Add soy sauce, gochujang (Korean red chili paste), and sugar, then stir well while frying.
Add green onion and stir-fry once more to finish.