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. Continue whisking until the marinade is homogeneous.
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 bag or cover dish and refrigerate for a minimum of 2 hours or up to 24 hours for optimal flavor and tenderness. Turn steaks occasionally if practical.
05 - Remove steaks from marinade, gently pat dry with paper towels, and discard marinade. Proceed to grill, pan-sear, or broil steaks to preferred doneness.