Preheat oven to 400 degrees.
Cut the tuna into large cubes, about 6 pieces.
Place the tuna on a non-stick baking sheet and insert it into the oven.
Bake the tuna for 10 minutes and remove it from the oven.
Sprinkle the cheese over the tuna and return the pan to the oven and bake for an additional 10 minutes.
Remove the pan from the oven and allow the tuna to cool before serving.