Super-thin skirt steak works best for carne asada, as it can stand up to powerful marinades like this one and cooks in just a few minutes over a hot grill. Serve the steak, sliced thin and across the grain, with tortillas and all the trimmings.
In a blender, combine the cilantro, garlic, onion, Worcestershire, chiles and 1 teaspoon salt. Blend the ingredients to make a smooth marinade.
Place the steak in a glass baking dish or tiptop plastic bag and pour the marinade over it. Rub the marinade all over the meat then refrigerate for at least 1 hour, up to several hours, to marinate.
Set up a charcoal grill for direct, high-heat cooking or heat a gas grill over medium-high. Lightly grease the grill with oil then add the carne asada. Cook, flipping the steak halfway through, until lightly charred and cooked to medium-rare doneness, about 2 to 4 minutes total.
Thinly slice and serve while hot.