In the bowl of a blender or food processor, pulse together marinade ingredients: 1/2 cup cilantro, 1/4 cup chopped green onion, 1/3 cup olive oil, 4 Tbsp Tabasco Chipotle Sauce, 1/2 tsp black pepper. Blend until smooth.
Place steak in a non-reactive dish (glass or plastic) and cover all sides with marinade. Cover with plastic wrap and refrigerate 6 hours or preferably overnight. Remove from refrigerator 30 minutes prior to grilling.
Grill over Medium-high heat (450˚F) for 4 min per side for medium rare, or cook to desired doneness. To create the fancy grilling marks, rotate 45˚ after 2 minutes. Remove to a plate and let rest 10 to 15 minutes prior to cutting. Cut steak (against the grain) into thin strips and serve.