Combine beef, water, soup mix, thyme, salt and pepper in stockpot; bring to a boil. Reduce heat; cover tightly and simmer 60 minutes.
Stir in barley; bring to a boil. Reduce heat; continue simmering, covered, 45 minutes to 1 hour or until beef is fork-tender and barley is tender. Stir in spinach; cover and remove from heat. Let stand 5 minutes. Season with salt and pepper, if desired.
Nutrition information per serving: 248 Calories; 81 kcal Calories from fat; 9 g Total Fat; 3 g Saturated Fat; 3 g Monounsaturated Fat; 76 mg Cholesterol; 294 mg Sodium; 13 g Total Carbohydrate; 3.5 g Dietary Fiber; 29 g Protein; 3.9 mg Iron; 4.2 mg Niacin; 0.3 mg Vitamin B6; 2.3 mcg Vitamin B12; 6 mg Zinc; 18.9 mcg Selenium; 100.9 mg Choline;