1: Make the marinade by placing all in the ingredients in a bowl to mix. ShareTweetPin29 Shares 2: Score the skirt steak in a crosshatch pattern on each side. Place the skirt steak in a resealable plastic bag and pour the marinade in the bag. Let the steak marinade in the refrigerator for a minimum of 4 hours, or as long as overnight.ShareTweetPin29 Shares 3: Make the chimichurri by placing all the ingredients in a food processor except the oil and the salt and pepper. Pulse the processor to chop the ingredients. Scrape down the sides of the processor. Pulse 3 to 4 times; repeat as needed. Once all ingredients are finely chopped, slowly stream in the oil with the machine running.ShareTweetPin29 Shares 4: Taste the chimichurri. Season with salt and pepper as needed. The fish sauce is salty; if salt is needed, add it in small amounts and taste.ShareTweetPin29 Shares 5: Heat thee grill to high. Scrape and oil the grates.ShareTweetPin29 Shares 6: Remove the steak from the marinade. Pat dry with a paper towel.ShareTweetPin29 Shares 7: Place the skirt steak on the hot grill and cook for 3 to 4 minutes on each side, depending in the thickness of the steak. ShareTweetPin29 Shares 8: Slice the skirt steak across the grain. Top with the chimichurri and serve immediately.ShareTweetPin29 Shares