01 - In a medium mixing bowl, whisk together soy sauce, olive oil, Worcestershire sauce, balsamic vinegar, and lemon juice until fully blended.
02 - Add minced garlic, Dijon mustard, brown sugar, black pepper, rosemary, and onion powder to the bowl. Whisk again to ensure all ingredients are thoroughly incorporated.
03 - Arrange steaks in a large resealable plastic bag or shallow dish and pour marinade over them, ensuring every piece is well coated.
04 - Seal the bag or cover the dish, then refrigerate for a minimum of 2 hours and up to 24 hours for optimal flavor and tenderness. Turn the steaks occasionally if possible.
05 - Remove steaks from marinade and pat them lightly with paper towels to remove excess. Discard remaining marinade. Cook steaks on grill, broiler, or in a pan to your preferred doneness.