1/2 c. vinegar
1/2 c. catsup
2 tbsp. oil
2 tbsp. finely chopped onions
2 tsp. chili powder
1 tsp. salt
1/8 tsp. pepper
3 lb. chuck or sirloin steak

Mix together first 8 ingredients. Pour over steak, let stand 3 hours or overnight in refrigerator. Pour off marinade and discard.

Grill until steak is slightly firm when pressed in center or until cooked to desired doneness.