In a small bowl whisk together everything except the flank steak.
Place flank steak in a resealable gallon ziplock bag. Pour marinade over the top of the steak. Squeeze as much air out of bag and seal. Place in the refrigerator 8 hours to marinate.
When ready to prepare steak heat your electric smoker to 225 degrees F and prepare according to manufacturer's directions. Place flank steak on smoker and smoke for 1 hour and 30 minutes or until the internal temperature is 135 degree F or your preference of doneness.