Trim away any excess fat from the flank steak and place in a shallow baking dish just large enough to hold the steak. In a blender or food processor, add the remaining ingredients, except the olive oil. Give it a good blitz and taste. Adjust seasoning to you favorite Bloody Mary. Then with the motor running on low speed, slowly pour in the oil until all combined. Pour the marinade over the steak and flip a couple time to coat. Cover and marinate in the refrigerator for at least 4 to 6 hours or for as long as overnight.
Preheat grill for direct cooking over high heat; if you have multiple burners, set and are to medium low for the scallions. Otherwise grill the scallions while the steak reposes after cooking. As always, brush and oil grates before cooking.
Place steak on hot grill at a 45° angle to the grates. Cook for about 4 minutes per side for medium rare. Allow the steak to rest (repose) for 7 or 8 minutes before slicing.
Once the steak has rested, thinly slice across the grain of the meat with your knife tilted at an angle to give you nice wide slices.
Recipe by Grilling Outdoor Recipes powered by Bull Outdoor Products at http://www.grillingoutdoorrecipes.com/cocktails-inspirations-bloody-mary-flank-steak/