Drain the oil from the canned tuna using a sieve.
Finely chop the onion, green onion, and spicy green chili pepper.
In a bowl, combine the tuna, chopped vegetables, doenjang (soybean paste), gochujang (red chili paste), minced garlic, and sesame oil. Mix well.
Add the mixture to a pan and stir-fry over medium-low heat for 3 minutes.
Finish by sprinkling sesame seeds on top.