In a medium bowl, combine soy sauce, cumin, oregano, lime juice, sugar, garlic, cayenne and parsley. Slowly whisk in the Bellucci EVOO. Place the flank steak and marinade into a gallon-size re-sealable plastic bag or a shallow baking dish and cover dish with plastic wrap. Marinate the steak, turning occasionally for at least 1 hour up to 8 hours.
Prepare and heat grill for cooking. Remove the steak from the marinade and pat dry with paper towels. Place steak on a hot grill and cook until seared with a good char on one side, about 4 minutes. Turn the steak over and grill second side to desired doneness, another 3-4 minutes depending on heat of the grill.
Transfer the steak to a cutting board and let rest 10 minutes. Prepare the Chimichurri Sauce. When ready to serve, slice the steak thinly across the grain and serve topped with Chimichurri sauce.
In the bowl of a food processor fitted with a metal blade add the parsley, garlic, oregano, vinegar, salt and chili flakes. Pulse until finely chopped. Stop the motor and scrape down the sides of the bowl. With the motor running, slowly pour the Bellucci Toscano PGI Organic EVOO through the feed tube and blend well. Transfer to a bowl.