In a pan add some oil, add the onion with the garlic and saute for 3 minutes in medium heat.Once the onions are translucent add the tomatoes and the peppers and cook for 3 minutes more.Add the tuna fish drained,the cilantro salt and pepper and mix it up, and cook for 5 minutes more in medium low heat.turn it off.Warm your corn tortillas, add some of the mixture and fold it like a quesadilla, you can secure it with toothpick if you like.Add some oil to a pan and fry them (I dont add a lot of oil so it will take a little longer)get them out of the pan and we like to add some slices of avocado inside the taco. Enjoy.