This Easy Tuna Snack is homemade tuna salad piled on top of a freshly sliced tomato, topped with cheese, and baked until the cheese is melted and bubbly.
Preheat oven to 450°F.
In a medium bowl, combine the tuna, mayonnaise, celery, pickles, and mustard. Mix well.
On a parchment-lined baking sheet, set out slices of tomato, top with tuna mixture, and a slice of cheese.
Bake for 7-10, or until cheese is hot and bubbly