Mix all the ingredients together. Marinade steak overnight in the fridge.
Remove the steak from the fridge and let sit out on the counter for 30 minutes while you prepare bbq grill.
Grill over medium-high for about 8 -12 minutes per side until the steak is cooked to the desired doneness. (Most other recipes I've read call for the steak to be grilled for a total of 9-12 minutes. This has always resulted in a totally super rare steak for me. I like my steak MR.)
Allow the steak to rest for about 10 minutes then slice on the bias and serve!
Notes
Plan Ahead: Since this dish requires marinating overnight, you’ll need to plan ahead. The marinade is a snap to make, so your time investment the day before devouring the steak is minimal. In a pinch, you can marinate the steak for a shorter amount of time, but it will result in a compromise in flavor.
Flank Steak Marinade: When you remove the steak from the marinade, discard it!
Bring To Room Temperature: Let your marinated flank steak sit out at room temperature for about 30 minutes before grilling. This will help the steak cook more evenly. When the meat is too cold, the outside will cook faster than the inside, which can lead to uneven doneness.
Preheat The Grill: It’s best to have your grill preheated to high heat (450- 500°F) before placing the flank steak on it.
Prep The Grates: Lightly oil the gas grill grates to prevent sticking. I use a few folded paper towels, dipped in oil, held with BBQ tongs to brush on the grates.
Sear It! Sear your steak over direct heat for approximately 3-4 minutes on each side, then move it as needed to a cooler part of the grill to finish cooking.
Carryover Cooking: Remember that after you pull the steak off the grill and let it rest, it will continue to cook from the residual heat. The internal temperature will rise a few degrees. Because of this phenomenon, it’s important to remove it from the grill when it’s slightly below your desired doneness. Grill flank steak to about 5°F.
Meat Thermometer: Unless you’re an extremely experienced griller, use an instant-read thermometer! I use them all the time and love them. Cook the flank steak to your desired doneness; medium-rare is recommended (about 130°F to 135°F internal temperature). Be careful not to overcook, as flank steak can become tough.
Rest It, Baby! This step is imperative to making a juicy flank steak. Doing so allows the natural juices to re-distribute. Remove the cooked flank steak from the grill to a cutting board, loosely cover it with aluminum foil, and let it rest for 7-10 minutes.
Slice It Up! When slicing the steak, do so against the grain. That is the opposite of the direction of the muscle fibers.