Cut beef into four 3/4-inch slices. Mix marjoram, sugar, and pepper and rub on both sides of beef slices. Heat oil in 10-inch skillet over medium heat. Cook beef in oil 3 to 5 minutes, turning once, until brown. Remove beef to serving platter and keep warm.
Over medium heat in skillet, cook mushrooms and onion in drippings for 2 minutes; stirring occasionally, until onion is crisp-tender.
Mix broth, wine, and cornstarch; stir into mushroom mixture. Cook over medium heat, stirring frequently, until mixture thickens and boils. Boil and stir 1 minute. Pour over beef.