Heat oil in large nonstick skillet over medium heat until hot. Add mushrooms and 1 teaspoon garlic; cook and stir 2 to 4 minutes or until mushrooms are tender and browned. Remove to medium bowl; cool slightly.
Meanwhile, combine remaining 2 teaspoons garlic and thyme. Press evenly onto beef steaks. Place steaks in same skillet over medium heat; cook 10 to 13 minutes for medium rare (145°F) to medium (160°F) doneness, turning occasionally. Remove to platter.
Add tomatoes, salad greens and vinaigrette to mushrooms; toss lightly to coat.
Season steaks with salt and pepper, as desired. Serve with salad.
Nutrition information per serving: 273 Calories; 126 kcal Calories from fat; 14 g Total Fat; 3 g Saturated Fat; 5 g Monounsaturated Fat; 67 mg Cholesterol; 182 mg Sodium; 8 g Total Carbohydrate; 2.4 g Dietary Fiber; 27 g Protein; 2.5 mg Iron; 10.6 mg Niacin; 0.7 mg Vitamin B6; 1.4 mcg Vitamin B12; 5.1 mg Zinc; 30 mcg Selenium; 126.4 mg Choline;