In a large glass baking dish whisk together Carne Asada marinade ingredients (jalapeño through black pepper) until combined. Add skirt steak in a single layer, turning to coat with marinade. Cover and refrigerate for at least 1 hour, but no longer than 8 hours (longer will begin to break down the meat - recipe note #3).
When you're ready to grill: preheat an outdoor grill to medium-high heat. Grill steaks for 7 to 10 minutes per side, turning once for medium-rare. Remove steaks and allow to rest for 5 minutes.
Slice thinly across the grain and serve.
Video
Notes
To make this version, we started with a recipe from Tyler Florence and switched it up to make it our own: swapping in apple cider vinegar, reducing the oil a bit and adding a third citrus flavor (lemon) and some cumin. Adding lemon juice to the mix happened by chance. I'd just finished a batch of homemade tonic water which left us with a slew of lemons, limes and oranges, flesh and juice intact, sans zest. And I love the citrus trifecta - now I may always use making tonic water as an excuse to make Carne Asada!
Ask your butcher or grocery meat counter for 'outside skirt steak' for the most flavorful and juicy results.
Note that the longer you marinate the skirt steak, the more tender and flavorful it will be come. But be sure to grill it within 8 hours to maintain the texture of the meat.