3 lbs. boneless chuck, 1 1/2" to 2" thick

Sprinkle both sides of meat with a tenderizer (optional). Place in a shallow pan.

MARINADE:

1/3 c. wine vinegar
2 tbsp. cooking oil
1 tbsp. Worcestershire sauce
1 tsp. salt
1/4 tsp. garlic powder
1/4 c. catsup
2 tbsp. soy sauce
1 tsp. prepared mustard
1 tsp. pepper