Shred the cabbage thinly.
Drain the oil from the canned tuna using a strainer.
Heat olive oil in a pan and stir-fry the cabbage.
When the cabbage softens, add the tuna and stir-fry together.
Season with soy sauce and black pepper.
Place the stir-fried cabbage and tuna on top of rice, and sprinkle seaweed flakes or sesame seeds as desired.