In a large skillet over medium-low heat, saute the pepper and onion rings in the butter until just tender. Remove to a plate and set aside.
In the same skillet, cook the steak, stirring, until cooked through. Divide the steaks into 2 portions and top each with a slice of cheese. Cover the skillet and continue cooking over low heat for about a minute, or just until the cheese is melted.
Place the steak and cheese portions on the bottom halves of the rolls. Divide the pepper and onion rings between the sandwiches, then top with the top half of the rolls.
Calories per serving: 547
Fat per serving: 20.6