01 - In a medium mixing bowl, whisk together the soy sauce, olive oil, Worcestershire sauce, balsamic vinegar, and lemon juice until thoroughly combined.
02 - Add minced garlic, Dijon mustard, brown sugar, black pepper, rosemary, and onion powder to the bowl. Whisk again until all ingredients are fully integrated.
03 - Arrange steaks in a large resealable plastic bag or shallow dish. Pour marinade evenly over the steaks, ensuring complete coverage.
04 - Seal the bag or cover the dish. Refrigerate for a minimum of 2 hours and up to 24 hours for optimal tenderness and flavor, turning the steaks occasionally.
05 - Remove steaks from the marinade, pat lightly with paper towels to dry, and discard any leftover marinade. Proceed to cook as preferred—grill, pan-sear, or broil to desired doneness.