In a blender, add marinade ingredients and blend on high speed for 15-20 seconds until smooth. Add steaks to a gallon-sized zip-lock bag, pour in marinade, squeeze out excess air and seal the bag. Massage marinade into all sides of the steak, then refrigerate for 1-4 hours.
Grilled Carne Asada:
Clean and oil cooking grate. Prepare a charcoal or gas grill fire for 2 zone, direct grilling over high heat (450-500°F). Cover and let warm-up for 10 minutes.
Once the grill is hot, remove steak from bag and wipe off excess marinade. Brush meat with 1 tablespoon of oil on all sides. Add steak to grill over direct heat for 3-5 minutes on each side to achieve a dark sear on the outside. Cover with lid while grilling. Remove from grill and let rest for 5 minutes. When ready, thinly slice steak against the grain.
Grilled Avocado:
While the steak is cooking, rub the flesh side of the avocado with 1 tablespoon of oil. Place on the hot side of the grill but not directly over heat, cook for 3-5 minutes on each side.
Lime-Cilantro Dressing:
In a blender, add lime juice, cilantro, salt, and pepper, and blend on high speed for 10 seconds. With the blender running slowly drizzle in oil. Vinaigrette should coat a spoon. Vinaigrette will keep for 5 days in the fridge.
Assemble:
To serve in a large bowl, season arugula with salt and pepper, pour 1/4 cup of the vinaigrette toss to cover the leaves evenly. Layer top with steak, avocado, cotija, and tomatoe. Serve with a side of dressing.
Do not marinate for longer than 8 hours because the meat will start to break down and get mushy.
Remove the steaks from the marinade. You can either toss the excess marinade, or you can transfer it to a small pot and bring to a boil for about 5 minutes then serve.
Use paper towels to pat each steak dry. It won't be perfect, but the drier they are when they hit the grill, the more browning effect we will get.
Grilling:
Remove steaks from the fridge and let them sit out return to return to room temperature.
Internal Temp:
The ideal internal temperature for grilled skirt steak is between 135°F medium-rare and 145°F medium.