Mince the garlic and oregano (a blender on ‘chop’ setting is the easiest way to do this).
Pour the minced garlic/oregano mixture into a bowl, add the balsamic, olive oil, honey, dijon, salt and pepper, and mix well.
Put the steak in a resealable bag and add the marinade. Squeeze all the air out of the bag and seal it, laying it flat and leaving it in the fridge to marinate for at least two hours (overnight is optimal). Flip it over occasionally so both sides have a chance to soak up the marinade.
Remove the steak from the marinade and let it come to room temperature. While it is warming up, add the remaining liquid from the marinade to a saucepan and bring it to a boil. Reduce it to a simmer and cook it down for about 10-15 minutes.
While reducing the sauce, preheat your grill to 375°-400° F. Cook for 5-6 minutes on the first side and then flip it, cooking for another 4-5 minutes.
Remove the meat from the grill and let it rest for at least 10 minutes.