3 lb. chuck roast (or larger; boneless)
1 tsp. monosodium glutamate (MSG)
1/3 c. vinegar
1/4 c. ketchup
2 tbsp. cooking oil
1/4 tsp. pepper
2 tbsp. soy sauce
1 tbsp. Worcestershire sauce
1 tsp. mustard
1 tsp. salt
1/4 tsp. garlic powder

Sprinkle both sides of roast with MSG. Place in shallow baking dish. Thoroughly combine remainder of ingredients. Pour mixture over roast and marinate for 2 to 3 hours, turning once or twice (may be marinated longer, if desired). Place roast on grill and broil about 6-inches from heat. Turn roast and baste with marinade every 10 to 15 minutes. Broil for a total of 35 to 45 minutes for medium-rare or until desired doneness.