For the Churrasco:
In a large mixing bowl, combine the olive oil, orange juice, lime juice, lemon juice, minced garlic, salt, pepper, and oregano. Whisk together until the ingredients are well incorporated.
Add the skirt steak to the bowl, ensuring that the marinade fully covers the meat. Cover and refrigerate for at least one hour, or up to eight hours for a more intense flavor infusion.
Once marinated, remove the steak from the bowl, discarding any large pieces of marinade. Preheat the grill to medium-high heat.
Place the steak on the grill and cook for approximately 4-5 minutes per side, or until the steak reaches your desired level of doneness.
After grilling, allow the steak to rest for a minimum of 5 minutes. Slice it thinly against the grain before serving.
For the Chimichurri Sauce:
In a small bowl, combine the shallot, minced garlic, red chili, parsley, cilantro, oregano, red wine vinegar, and olive oil. Stir until all ingredients are thoroughly mixed.
Season with salt and pepper to taste, then drizzle the chimichurri sauce over the sliced churrasco before serving.