Heat broiler. Coat a broiler pan with nonstick spray.
Season steaks with salt and pepper. Place on prepared pan and broil for 3 to 4 minutes per side for medium rare or until internal temperature reads 130 degree F on an instant-read thermometer. Keep warm and allow to rest for 5 minutes.
Meanwhile, heat a large nonstick skillet over medium-high heat. Add the olive oil, mushrooms and garlic and cook, stirring occasionally, for 5 minutes. Stir in steak sauce, onion flakes, brown sugar and 1/4 cup water. Cook, stirring occasionally, for about 3 minutes, until thickened.
Serve with salad and asparagus, if desired.