In a large bowl, combine the orange juice, soy sauce, ¼ cup of cilantro, three tablespoons of lime juice, vinegar, garlic, oregano, cumin, 1 teaspoon of salt, black pepper, and chili powder.
Transfer the steak to a large ziplock bag and carefully pour the marinade into the bag covering the steak. Seal the bag, removing as much air as possible. Transfer to the refrigerator for at least 1-4 hours (at least 4 hours for flank steak) but no more than 12 hours.
When ready to cook, heat a large cast iron grill pan over high heat. Coat with oil.
Once the pan is hot, remove the steak from the marinade and discard the excess marinade that was used to season the beef. Cook the beef for 6-9 minutes on each side or until it is cooked to your preference (Cooking time will vary depending on how thick your meat is).
Remove the steak and allow it to rest for 5-10 minutes before thinly slicing against the grain into thin strips, then again in the opposite direction to make small bite-size pieces.
Meanwhile, in a medium bowl combine the onion, remaining cilantro, remaining lime juice, and salt. Mix well to combine.
Heat the corn tortillas in a small pan with a bit of oil (optional) over medium heat until softened. Scoop 1-2 spoonfuls of carne asada into the center of the tortilla followed by a scoop or two of the onion and cilantro salsa.
Serve garnished with fresh lime juice and green salsa (or other favorite toppings).