Combine soy sauce, barbecue sauce, peanut butter and garlic powder in small bowl; stir to combine thoroughly. Place beef steaks and soy sauce mixture in food-safe plastic bag; turn to coat steaks. Close bag securely and marinate in refrigerator 6 hours or as long as overnight, turning occasionally.
Remove steaks from marinade; discard marinade. Place steaks on rack of broiler pan so surface of beef is 2 to 3 inches from heat. Broil 10 to 13 minutes for medium rare (145°F) to medium (160°F) doneness, turning once. During last 3 minutes of broiling top steaks with green onions.
Carve steaks diagonally across grain into thin slices. Serve with green onions.
Nutrition information per serving: 353 Calories; 180 kcal Calories from fat; 20 g Total Fat; 8 g Saturated Fat; 10 g Monounsaturated Fat; 116 mg Cholesterol; 845 mg Sodium; 7 g Total Carbohydrate; 1.1 g Dietary Fiber; 34 g Protein; 4 mg Iron; 12 mg Niacin; 0.7 mg Vitamin B6; 5.5 mcg Vitamin B12; 7.6 mg Zinc; 24.4 mcg Selenium; 122.2 mg Choline;