Preheat the oven to 400F and open and drain the tuna cans.
Mix the drained tuna, mayonnaise, black pepper, cajun seasoning, mustard, onion powder, and garlic powder in a large bowl until well combined.
Separated the English muffin halves and place face up on a sheet pan. Spoon a heap of the tuna mix onto each English muffin until all tuna mixture is used up.
Divide the cheese evenly over all of the tuna covered english muffins and place in the oven.
Bake for 5-10 minutes, until the cheese is melted and the tuna is warm. Serve and enjoy!