Cut the fish cakes into bite-sized pieces.
Slice the onion and green onion thinly.
Add cooking oil to a pan and stir-fry the green onion to make green onion oil.
Add the onion and fish cakes and stir-fry together.
Put in gochujang (Korean red chili paste), chili powder, soy sauce, and oligosaccharide, then mix evenly while stir-frying.
Add a little water and simmer, coating the fish cakes evenly with the sauce.
Finish by drizzling sesame oil and sprinkling sesame seeds.