Prepare the Tuna Salad: In a mixing bowl, combine the drained tuna, mayonnaise, mustard, hot sauce, chopped celery, chopped red onion, pickles, jalapenos, salt, black pepper, and garlic powder. Mix until all ingredients are well incorporated.

Preheat the Air Fryer: Set your air fryer to preheat at 350 degrees F for a few minutes.

Prepare the Bread: Place the bread slices on a baking sheet or directly in the air fryer basket. Toast them lightly for about 2 minutes to ensure they're sturdy enough to hold the toppings.

Add the Tuna Mixture: Spread the prepared tuna salad evenly over the toasted bread slices, covering them completely.

Top with Cheese: Top with a thin layer of shredded cheese, the fresh tomato slice, then another layer of cheese.

Air Fry: Carefully place the topped bread slices in the preheated air fryer basket. Air fry for 4-5 minutes or until the cheese is melted and bubbly, and the edges of the bread are crispy. You can turn up the heat to 450 at the end for 1 minute to brown the cheese if desired.

Serve: Once done, remove the open-faced tuna melts from the air fryer. Allow them to cool slightly before serving to avoid burning your mouth.