Whisk together balsamic vinegar, soy sauce, oil, worcestershire sauce, honey, Italian seasoning, garlic powder, and dried mustard.
Add steaks and marinade to a zip lock bag, tossing the steaks a few times to coat. Press the excess air out, seal the bag, and chill for 15-20 minutes.
Use tongs to transfer steaks to a preheated grill. Cook until desired doneness is reached. Allow to rest for 5 minutes before serving. Garnish with fresh parsley if desired.
Video
Notes
Marinating time: don't marinate too long. 15-30 minutes is plenty of time for this marinade!