Add the flank steak to the marinade, make sure that it’s fully covered in the marinade, and seal trying to remove as much air as possible. Marinate in the fridge for at least 2 hours and up to 8 hours.
Pulse until finely chopped NOT pureed, alternatively chop by hand with a sharp knife. Remove onto a bowl, add olive oil and gently stir. Allow to sit for an hour before using.
Increase the smoker temperature to 450°F/230°C, and sear the steak for 3 minutes per side. The internal temperature of the steak must be 135°F/57°C for medium rare.