3/4 c. olive oil
1/2 c. soy sauce
2 tbsp. Worcestershire sauce
1 tbsp. dry mustard
1 tsp. salt
1 tsp. pepper
1/4 c. wine vinegar
1 tsp. dry parsley flakes
1/4 c. lemon juice
2 cloves garlic, crushed (optional)

Mix well and store in refrigerator. Marinate steak, depending on quality of cut, 3 hours. For chuck, less time for more expensive cuts, and cook.