Cut the kimchi into bite-sized pieces.
Finely chop the onion.
Heat some cooking oil in a pan and sauté the onion and kimchi.
When the kimchi turns translucent, add the tuna and stir-fry.
Add the rice and mix all the ingredients evenly.
Taste and season with salt or pepper as needed.
Turn off the heat and sprinkle pizza cheese on top of the rice.
Cover with a lid and wait until the cheese melts.