Heat butter or oil in a large skillet over medium-high heat. Add peppers, steak, and seasonings and cook for about 5 minutes, or until peppers are tender. Turn heat off and top the hot steak and peppers with the cheese and let melt. Meanwhile, divide salad mix evenly between 2 bowls. Divide the hot mixture evenly over the bowls of salad, and serve immediately.
Recipe courtesy of George Stella