Combine olive oil, vinegar, honey, soy sauce and minced garlic in a large ziploc bag.
Add flank steak to the marinade; seal and refrigerate for 2 hours, and up to 8 hours.
Preheat grill to 375˚F to 400˚F.
Once preheated, oil the grill grates with cooking oil.
Remove steak from marinade; discard marinade.
Lightly pat dry the steak with paper towels.
Season with salt and pepper.
Grill steak, covered, for 8 minutes; flip over and continue to grill, covered, for 6 more minutes, or until internal temperature reaches 135˚F to 140˚F for medium-rare.
Remove steak from grill and let rest for at least 5 minutes before cutting.
In the meantime, prepare the compound butter by combining the butter and bleu cheese in a small mixing bowl. Using the back of a fork, mix and mash until blended.
Serve steak with compound butter and enjoy!