Mr. Head's Spicy Tuna Melt

Heat the vegetable oil in a skillet over medium heat. Add the onions and celery and season with a little kosher salt. Cook and stir until tender, about 5 minutes. In a medium bowl, stir together the tuna, mustard, mayonnaise and the sauteed onion and celery. Season with cayenne, blackened seasoning, parsley, and hot pepper sauce. Spoon onto half of the bread slices. Top each one with a slice of pepperjack cheese and then the remaining slices of bread. Spread butter onto the outsides of the sandwich. Fry in a skillet over medium heat until golden brown on the outside and cheese has melted, about 5 minutes total.