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 thoroughly combine all components.
03 - Arrange steaks in a large resealable plastic bag or shallow dish. Pour marinade over steaks, ensuring each piece is evenly 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 steaks periodically if possible.
05 - Remove steaks from marinade, lightly pat dry with paper towels, and discard used marinade. Proceed to grill, pan-sear, or broil to preferred doneness.