01 -
In a mixing bowl, combine drained tuna, mayonnaise, Dijon mustard, garlic powder, onion powder, salt, and black pepper. Stir in finely diced jalapeño, shredded sharp cheddar cheese, and green onions if using.
02 -
Butter one side of each bread slice. Place the buttered side down on a skillet preheated over medium heat. Sprinkle shredded cheddar on one slice, spread the tuna salad evenly on top, then cover with the second slice, buttered side up.
03 -
Cook sandwiches for 3 to 4 minutes per side, pressing gently with a spatula, until bread is golden brown and cheese is melted. Remove from heat and let rest for one minute before slicing.
04 -
Slice sandwiches in half and serve hot with preferred sides such as pickles, chips, or a fresh salad.