Finely chop the onion and green onion.
Heat olive oil in a pan and sauté the onion and green onion.
Add the tuna and stir-fry together.
Add Buldak sauce and mix well.
Add the rice and cook until it is evenly seasoned.
Pour in the milk and bring to a simmer.
Top with cheese, cover with a lid, and wait until the cheese melts.
Finish with pepper to taste, if desired.