In a zip-top plastic bag, combine lime juice, zest, garlic, cilantro, soy sauce, oregano, cumin, and pepper to taste. Pierce steak all over with fork then place in the bag. Seal top and turn bag to coat meat thoroughly with marinade. Marinate, refridgerated, 1-2 hours. Drain well.
Broil or grill steak until desired doneness. Slice into thin strips and serve.