01 - Whisk together soy sauce, olive oil, Worcestershire sauce, balsamic vinegar, and lemon juice in a medium mixing bowl until fully blended.
02 - Add minced garlic, Dijon mustard, brown sugar, black pepper, rosemary, and onion powder. Whisk again until all ingredients are thoroughly integrated.
03 - Arrange steaks in a large resealable plastic bag or shallow dish and pour marinade over. Ensure each piece is evenly coated.
04 - Seal or cover and refrigerate for at least 2 hours, preferably up to 24 hours, turning steaks occasionally for optimal flavor penetration and tenderness.
05 - Remove steaks from marinade, pat lightly dry with paper towels, and discard used marinade. Cook steaks using preferred method: grill, pan-sear, or broil to desired doneness.