Finely chop cabbage and onion.
Drain the tofu and mash it.
Drain the oil from the canned tuna using a strainer.
Heat cooking oil in a pan and stir-fry the onion and cabbage.
Add tofu and tuna, and stir-fry together.
Add the rice and stir-fry, mixing evenly.
Season with soy sauce, salt, and pepper to taste.
Place the finished fried rice in a bowl.