Heat a large nonstick skillet over medium-high heat.
Sprinkle steaks with salt and pepper; coat with cooking spray.
Add steaks to pan; cook 3 minutes on each side or until desired degree of doneness.
Transfer steaks to a serving platter; keep warm.
Add mushrooms to pan. Coat mushrooms with cooking spray; saut 3 minutes or until browned. Stir in wine, scraping pan to loosen browned bits. Cook until liquid almost evaporates.
Remove pan from heat; add butter and rosemary, stirring until butter melts.