– tuna – mayonnaise – dijon mustard – celery
In a bowl, combine drained tuna, mayonnaise, Dijon mustard, diced celery, red onion, chopped dill pickles, and season with salt and pepper to your preference.
Arrange the bread slices on a baking sheet and broil on low heat until the cheese is melted and bubbly, about 2-3 minutes.