In a blender or food processor, combine the cilantro, oil, lime juice, garlic, oregano, brown sugar, cumin, orange juice, soy sauce, salt, and black pepper. Blend until smooth and fully combined into a vibrant marinade.
Place the skirt steak into a large resealable bag or shallow dish and pour the marinade over the meat. Cover tightly and refrigerate for at least 2 hours, though overnight will give the steak even deeper flavor.
Preheat your grill for direct high heat, aiming for around 600°F using charcoal or a very hot gas grill setup. High heat is key for developing a flavorful crust on the steak without overcooking the inside.
Remove the steak from the marinade and allow any excess marinade to drip off before placing it directly over the hot grates. Sear for about 2 minutes per side until a deep caramelized crust forms and the steak reaches your desired doneness.
Transfer the steak to a cutting board and let it rest for 10 minutes before slicing. Resting helps the juices redistribute throughout the meat, keeping every bite tender and juicy.
Slice the steak thinly against the grain, then chop into bite-sized pieces for tacos. Serve on warm tortillas with pico de gallo, queso fresco, chipotle crema, and fresh lime wedges.