I cut the steak into strips and made fajitas.  You can keep it whole and serve with sides.

 
    * 1/4 cup cumin seeds

    * 1 1/2 teaspoons freshly ground black pepper

    * 1 cup olive oil

    * 1/2 cup freshly squeezed lime juice

    * 3 bunches cilantro, including stems

    * 4 cloves garlic

    * 4 jalapeno chiles, cut in half lengthwise

    * 3 pounds skirt steak, trimmed and cut into 6 serving pieces

    * 1 1/2 teaspoons kosher salt

Instructions

   1. Lightly toast the cumin seeds in a dry skillet over high heat until their aroma is released, 1 to 2 minutes, shaking the pan taking care not to burn them. Combine the cumin seeds, olive oil, lime juice, jalapeno chiles, garlic, salt, and black pepper in the jar of an electric blender and puree until smooth. Scrape down the sides, add the cilantro, and pulse until just blended. Rub the meat generously with the marinade, roll the pieces up into tight logs, put them in a resealable plastic bag, and refrigerate for 24 hours to 48 hours, turning once or twice.

   2. Heat a gas or charcoal grill or broiler until it is very hot. Position the rack about 4 inches from the heat. left the steaks from the marinade and grill each side until seared, 3 to 4 minutes, turning once. Discard the marinade. Remove to a warm platter, let rest for 5 minutes, and then transfer the steaks to a cutting board, slice across the grain into thin strips, and serve.

Taste:  5/5  I used powdered cumin and pan-fried steak strips for fajitas.  As you can see from the photo, the meat was very juicy.  This was the only time I can recall I put no salsa on the fajias because the meat was so juicy and good.
Leftoverability: 4/5  not as juicy the second time around, but made a great topping for a steak salad.
Brit-rating:  HATEd it:  "I prefer your other fajitas."
Serve to guests:  The recipe would rival any Mexican restaurant, so I would definitely serve it to guests.