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. Whisk until completely incorporated.
03 - Place steaks in a large resealable plastic bag or shallow dish. Pour marinade evenly over steaks, ensuring thorough coating.
04 - Seal bag or cover dish, then refrigerate for a minimum of 2 hours, preferably up to 24 hours for optimal flavor and tenderness. Turn steaks occasionally during marination if possible.
05 - Remove steaks from marinade, pat dry with paper towels, and discard used marinade. Proceed to grill, pan-sear, or broil to desired doneness.