This tuna melt sandwich is not only super delicious but also super quick and easy to make.
In a bowl mix together the tuna, celery, mayonnaise and black pepper.
Butter two slices of bread on one side each.
Heat up skillet over medium heat. Once hot, place one slice of bread butter side down in the skillet.
Add two slices of cheese on top of the bread. Then add a few tablespoons of tuna on top and the sliced red onion if desired. Top with the other slice of bread butter side up.
Let cook for about two minutes or until the bottom is browned. Then flip the sandwich and continue cooking for another two minutes or until the bottom has browned.
Repeat the above instructions with the remaining slices of bread.
Enjoy!