
In a mixing bowl, combine tuna, mayonnaise, onion, and celery; mix well. Top 4 of the bread slices each with 1 slice of cheese. Spread tuna mixture over cheese slices and top with remaining bread slices. Spread each sandwich with additional mayonnaise; place in skillet. Cook on medium heat until lightly browned on both sides.
Tip: carrot and cucumber may be substituted for onion and celery.
Prep Time: 10 minutes
Cook Time: 5 minutes
Serves: 4