Trim the fat: Prepare your steak by trimming off the fat. Also, peel off any remaining membrane from the surface of the meat.
Season both sides of the skirt steak generously with salt and pepper.
Make the marinade: In a resealable plastic bag, add garlic, lime juice, soy sauce, olive oil, Worcestershire sauce, ginger, Italian seasoning, green onions, and optional red flakes and herbs.
Place the steak in the bag, close the bag and shake to coat the meat evenly from all sides. Let it marinate for at least 30-60 minutes at room temperature. (Marinate the steak in the refrigerator if not cooking within 1 hour)
Prepare the grill: Preheat grill to medium-high heat 400-450°F (204-232°C). Grease the cooking grates with the oil to prevent sticking. (Make sure the grates are hot enough before putting the steak on.)
Grill the steak: Once the grill is ready, remove the steak from the marinade and wipe off the excess liquid with paper towels. Place the steak on the grill, cover and cook for 2-3 minutes.
Open the grill and flip the steak. Cover and grill the other side for 2-3 minutes.
Check doneness: Insert an instant meat thermometer into the thickest part of the steak. Remove from the grill at 120°F (51°C) for rare, 125°F (52°C) for medium-rare, and 135°F (57°C) for medium. (As the temperature will rise a few degrees while resting.)
Rest the Meat: Remove your steak to a cutting board and let it rest covered with aluminum foil for 5-10 minutes. This allows the juices to redistribute through the meat.
Slice thinly and serve.