Finely chop the cabbage.
Beat the egg in a bowl.
Heat oil in a pan and stir-fry the cabbage.
Drain the tuna and add it to the pan, stir-frying together.
Pour in the beaten egg and cook, scrambling them.
Add the rice and stir-fry everything together.
Season with soy sauce or salt to taste.
Serve in a bowl and enjoy.