Place your skirt or flank steak into a large zip-top bag
Place all of your marinade ingredients (minus the cilantro) into the work bowl of a small food processor or blender - Purée into a smooth paste
Add the puréed marinade mixture to the zip-top bag along with the fresh cilantro - Remove as mush air as possible and seal the bag - Allow to marinate for a minimum 2 hours (overnight for better results)
Heat your grill to HIGH heat (450-500°) - NOTE: A charcoal or mesquite wood fire is preferred for authentic flavor, but a gas grill (or stove top grill pan) will work just as well
Once the grill is HOT, quickly rub the grill with half an onion to clean and flavor it (and to keep the meat from sticking) - Remove the steak from the marinade, shake off any excess, and place on the grill - Allow to cook undisturbed until the meats juices rise to the surface (apx 3-4 minutes) and the meat lifts away easily from the grill - Flip and repeat for the other side - You are looking for is a nice crispy / charred exterior without over cooking the meat (no more than 135-140°F interior temp) so HOT and quick is necessary!
Transfer to a cutting board and allow to rest for 5 minutes - Thinly slice across the grain into ribbons
Serve alongside grilled spring onions, pico de gallo or salsas of choice with some lime wedges or use to fill tacos, burritos, lettuce wraps, quesadillas, or flautas. Use to make ‘burrito/taco bowls’ or to top a salad, nachos, or eggs - Just use your imagination! For Authentic Mexico City Style Carne Asada Street Tacos:Serve with warm corn tortillas, diced white or red onion, fresh cilantro, lime wedges, guacamole or avocado crema, and salsas of choice