Prepare the marinade by whisking together olive oil, red wine vinegar, minced garlic, cumin, smoked paprika, salt, pepper, and oregano in a large bowl until well combined.

Marinate the steak by placing the trimmed skirt steak in a large resealable bag or shallow dish, pouring the marinade over the meat, and ensuring all surfaces are coated. Refrigerate for at least 2 hours or up to 24 hours.

Make the chimichurri sauce by finely chopping the parsley and cilantro, then combining them with minced garlic in a bowl. Slowly whisk in olive oil, red wine vinegar, lemon juice, salt, red pepper flakes, and black pepper.

Allow the chimichurri to rest at room temperature for at least 30 minutes to let the flavors meld.

Preheat your grill to high heat, ensuring the grates are clean and well-oiled to prevent sticking.

Remove the steak from marinade and let it come to room temperature for 15-20 minutes while the grill heats up.

Grill the steak for 3-4 minutes per side for medium-rare, or adjust timing based on your preferred doneness.

Rest the cooked steak on a cutting board for 5-10 minutes to allow juices to redistribute.

Slice against the grain into thin strips, cutting perpendicular to the visible muscle fibers.

Serve immediately with generous spoonfuls of chimichurri sauce on top and alongside the sliced steak.