Press down firmly on tuna can lid and drain juice from the tuna. In a bowl, combine the drained tuna, mayonnaise, slaw dressing, Dijon mustard, relish, celery, red onion, garlic, cilantro, lemon juice salt and pepper. Mix to combine. Spread mayonnaise on both sides of bread slices. Place in hot skillet and brown on one side. Turn bread over and add one slice of cheese and 2 tablespoons of mozzarella, spreading evenly over bread. Spoon tuna over shredded mozzarella. Put the sandwich together and continue to cook on low heat long enough for cheese to melt. Serve hot.