For two 1 lb. flanks steaks (increase batch as required for more meat):

5 oz. soy sauce
1/3 C. vegetable oil
2 T. Lea & Perrins Worcestershire
2 T. lemon juice
2 T. red wine vinegar
2 t. Italian seasoning
2 T. sliced green onion tops

Mix marinade ingredients together. Place flank steaks in 1 gallon zipper bag and pour in marinade. Squeeze out excess air and seal bag. Refrigerate overnight (18-24 hours), flipping bag occasionally. Grill over medium heat, about 10 minutes per side for medium. Slice thin across grain on the bias.

Tips: 1. Extra marinade can be used to baste during grilling. 2. Marinade made up in advance without Italian seasoning and green onion can be kept refrigerated for weeks. 3. Grill zucchini or other veggies halved length-wise, skin side-down; baste with marinade.