A Tuna Melt is a popular sandwich made with canned tuna, mayonnaise, and often other ingredients like celery, onion, or cheese. The mixture is typically spread between two slices of bread, which can be toasted or grilled to create a warm, melty texture. The sandwich is usually topped with a slice of cheese, such as cheddar or Swiss, and then heated until the cheese melts. Tuna Melts are commonly served with sides like potato chips or a salad, making them a satisfying meal option for lunch or dinner.