Wash the cabbage and slice it thinly.
Drain the oil from the canned tuna using a strainer.
Heat cooking oil in a pan and stir-fry the cabbage.
When the cabbage softens, add the tuna and continue stir-frying.
Season with soy sauce, pepper, sugar, etc.
Place the stir-fried cabbage and tuna on top of the rice.
Add seaweed flakes, green onions, or other toppings as desired.