01 - In a medium mixing bowl, whisk together soy sauce, olive oil, Worcestershire sauce, balsamic vinegar, and lemon juice until thoroughly blended.
02 - Add minced garlic, Dijon mustard, brown sugar, black pepper, rosemary, and onion powder to the bowl. Whisk until all elements are fully integrated.
03 - Arrange steaks in a large resealable plastic bag or shallow dish. Pour marinade over the steaks, ensuring all surfaces are coated evenly.
04 - Seal the bag or cover the dish, then refrigerate for at least 2 hours and up to 24 hours for maximum flavor penetration. Turn steaks occasionally if possible.
05 - Remove steaks from marinade, gently pat dry with paper towels, and discard used marinade. Cook steaks using grill, broiler, or skillet to preferred doneness.