1. Sprinkle steaks evenly with 1/4 teaspoon pepper and 1/8 teaspoon salt. Heat oil in a large nonstick skillet over medium-high heat. Reduce heat to medium. Add steaks to pan; cook 2 minutes on each side or until desired degree of doneness. Remove from pan; keep warm.
2. Add mushrooms to pan; cook 5 minutes or until tender and beginning to brown, stirring frequently. Combine wine, 1/2 cup water, flour, 1/8 teaspoon pepper, and 1/8 teaspoon salt; stir well with a whisk. Add wine mixture to pan; bring to a boil. Cook 2 minutes or until thick; stir constantly. Remove from heat.
3. Prepare potatoes according to package directions. Stir in chives and garlic powder. Place 3/4 cup potatoes on each of 4 plates. Top each with 1 steak and about 1/4 cup mushroom sauce.