Combine all ingredients together and pour over steak in a shallow dish or zip-top bag.

Refrigerate and allow the steak to marinate for at least one hour or overnight. During the marinating process turn several times to make sure everything is combined and the steak is getting full coverage.

Grill over a charcoal or gas grill until done to your desired doneness.

It's hard to say exactly how long in time to grill a flank steak. I typically use a quick read thermometer and do not cook based on any number of minutes. I like my flank steak medium rare so I pull it off the grill when the internal temperature is between 125 and 130 degrees F. If you simply must have a time frame, I would start with grilling the steak for 5 minutes per side.

Allow the steak to rest for 10 to 15 minutes before slicing.

Slice steak against the grain and serve.