3/4 c. salad oil
3/4 c. soy sauce
1/4 c. Worcestershire sauce
2 tbsp. dry mustard
2 tsp. salt (celery salt, garlic salt, onion salt, etc.)
1/2 c. wine vinegar
1 1/2 tsp. dried parsley
1/3 c. lemon juice

Mix all ingredients and marinate flank steak for several hours before grilling or broiling, can marinate overnight.