- Mix stock, wine, thyme, garlic powder and pepper in medium bowl until well blended. Add mushrooms; toss to coat well.
- Melt butter in large non-stick skillet on medium high heat.
- Add steaks; cook 8-10 minutes or until desired doneness, turning once. Remove steaks from skillet; keep warm.
- Add onion to skillet; cook and stir 2 minutes or until softened. Add flour and salt; cook 1 minute, stirring constantly.
- Pour mushroom mixture into skillet. Boil 10 to 12 minutes or until sauce is thickened and mushrooms are tender, stirring occasionally. Add steaks to sauce: heat 1 minute. Serve immediately.