Start off by prepping all of your ingredients for the Chimichurri and the marinade. In a medium-sized bowl place your skirt steak in it. Now add the dry seasoning: Chili powder, black pepper and salt. Follow this up with lemon juice, garlic, orange juice, onion, jalapeños and cilantro. Hand toss to make sure the marinade covers the beef. Place in the fridge for 4 hours.
Now add all of your ingredients for the Chimichurri into a separate bowl. Parsley, cilantro, oregano, scallions, shallots, garlic, jalapeño, olive oil, red wine vinegar, kosher salt and red pepper flakes. Whisk with a fork and place in the fridge. Let it sit for 2-4 hours, this lets the flavors marry together.
After the four hours passes remove the meat from the fridge and fire up your grill. I had a griddle for this cook with my surface temp of 450 degrees. I grilled my steaks for 2 minutes and flipped, grilled another 2 minutes, flip and grill for 1 minute and flip for a final 1 minute. Remove the steak from the griddle and rest for 8-10 minutes.
While the meat is resting, cut your buns in half and apply some butter. Place them on the griddle to toast for 1 – 1 1/2 minutes. Now cool the griddle to 350 degrees and add the shredded cheese in the form of the buns. Let the cheese crisp and melt. Now add the buns to the cheese blankets and let them sit for 30 seconds. Remove them from the griddle.Grilled skirt steak on loco griddle
Slice the steak against the grain to fit your sandwich. Add the Chimichurri to the bottom bun, and add the sliced steak and more chimichurri. Add the top bun and it is complete.