Trim the beef and cut into 1 1/2-inch cubes. Place in a shallow pan and set aside.
Add the olive oil, vinegar, lime juice, jalapeños, garlic, parsley, oregano, and red chile flakes to the bowl of a food processor fitted with the steel blade. Blend for 30 seconds, season with salt and pepper, then process for another 10 seconds.
Pour half of the sauce over the beef, reserving the remainder. Toss the meat in the marinade until completely coated and refrigerate for 4 to 8 hours.
If using bamboo skewers, place the skewers in a pan and cover with water. Soak for 1 hour. Heat your grill to 450 degrees F.
Remove the beef from the marinade and divide it into 4 (8-ounce) portions. Discard the used marinade. Thread the meat on the skewers and then place the skewers on the grill. Close the lid; turn the skewers every two minutes for a total of eight minutes for medium-rare to medium, making sure to grill the meat on all sides. Transfer the skewers to a platter and let the meat rest for five minutes before serving. Serve with the remaining sauce.
