Place the garlic, cumin, and cilantro in a food processor and blend till coarsely chopped.
Add the chilis(this will be quite spicy-use less if desired), olive oil, salt, and pepper and process until smooth.
Rub the chili mixture onto the steak. Let the steak stand at room temperature 2-3 hours(or in the refrigerator overnight). If you refrigerate, allow the meat to come to room temperature before grilling.
Grill over a hot falme for about 5 minutes per side for medium rare, a few minutes longer for well done. Enjoy!