Directions

1. Divide sirloin into four equal portions, and form patties, each about 1 inch thick and 4 inches in diameter. Be careful not to overhandle the meat, which compresses and toughens it. Place a small amount of blue cheese in the center of each patty, if desired. Rub patties lightly with a very small amount of olive oil.
2. Heat a cast-iron skillet over high heat until very hot. Place patties in skillet, and cook for 4 minutes. Turn, and season with salt and pepper. Top with cheese, if desired, cover, and cook 3 minutes more for medium-rare.
3. Meanwhile, slice open buns, and toast them; spread with butter, if desired. When burgers are done, serve on toasted buns with any combination of the following: onions, bacon, tomatoes, lettuce, ketchup, mustard, mayonnaise, and relish.