01 -
Combine tuna, mayonnaise or Greek yogurt, Dijon mustard, garlic powder, onion powder, salt, and black pepper in a mixing bowl. Stir in diced jalapeños, shredded sharp cheddar, and green onions if using.
02 -
Butter one side of each bread slice. Place slices buttered side down on a skillet over medium heat. Sprinkle shredded cheddar cheese on one slice, spread tuna salad evenly on top, then place the second slice of bread buttered side up on top.
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 1 minute.
04 -
Slice each sandwich in half and serve immediately, optionally with pickles, chips, or a side salad.