In a mixing bowl, whisk together olive oil, soy sauce, red wine vinegar, minced garlic, oregano, black pepper, and salt.

Place the skirt steak in a resealable plastic bag and pour the marinade over it. Seal the bag and refrigerate for at least 1 hour, preferably overnight.

In a bowl, combine chopped parsley, olive oil, red wine vinegar, minced garlic, red pepper flakes, salt, and black pepper. Mix well and set aside.

Preheat the grill to high heat. Remove the steak from the marinade and discard the marinade.

Grill the steak for about 4-5 minutes on each side for medium-rare, or until desired doneness.

Let the steak rest for 5 minutes before slicing against the grain.

Slice the skirt steak and serve with chimichurri sauce drizzled on top.