Roast beef steak (sirloin) is cut from the lumbar section of the beef carcass. The meat is marbled, that is, it contains streaks of fat that impart softness.
In a large skillet over high heat, heat 3 tablespoon. tablespoons of butter and all vegetable oil. Place the steaks in a preheated pan, cook for about 1 minute on each side (turn the steaks only with tongs).
Reduce heat to medium and cook meat for an additional 3-5 minutes on each side or until cooked to the desired degree. Season the steaks with salt and pepper and transfer to serving bowls, cover with foil to keep the meat warm.
Pour the beef broth into the same pan, cook over medium heat, scraping off the fat from the pan for a couple of minutes. Add butter, cook for a couple of minutes. Pour this sauce over the meat and serve with the French fries (optional) right away.