Drain the oil or water from the can of tuna and set aside.
Finely chop the onion and green onion.
In a bowl, mix the tuna, chopped onion, green onion, egg whites, salt, and pepper together.
Add olive oil to a pan and heat over low heat.
Spoon the mixture onto the pan one spoonful at a time and cook until golden brown.
Flip and cook both sides evenly.