Combine the cumin, paprika, red chili flakes, all-purpose rub, vegetable oil, lime juice, soy sauce, Worstishire sauce, ginger, and sliced scallions in a bowl large.
Place the marinade and steak in a ziplock bag then chill for two hours turning every half hour.
Dressing
In a bowl add the olive oil, lime juice, cumin, garlic, all-purpose rub, salt, and pepper.
Whisk lightly to start the emulsification process so the oil is incorporated.
Chill until ready to assemble the salad.
Mexican Salad
In a large bowl add the black beans, cheese, tomatoes, onion, avocado, radish, cucumber, and cilantro. Put aside until needed.
Roasted Corn on the Cob
Soak the corn for 30 minutes submerged in water.
Preheat a charcoal grill to a high temperature.
Pull the husks back–but not off–to access the corn silks, remove all the corn silks then put the husks back in place. Cut off a couple of outer husk layers to use as twine to keep the husks in place.
Roast indirectly on the preheated grill for about 30 minutes until softened.
Remove husks then grill directly over coals briefly to slightly char the corn.
Cut the kernels off the cob and set aside.
Grilled Steak
Grill the skirt steak directly over white hot coals with a couple of wood chunks for a couple of minutes on each side, until cooked to your prefered doneness.
Let rest for 10 minutes before slicing for the salad.
To Assemble
Add the grilled corn to the salad ingredients then drizzle with half the salad dressing. Toss to combine.
Serve the salad on serving plates.
Slice the rested grilled skirt steak against the grain then serve over the individually portioned salads.
Serve the skirt steak Mexican salad with the remaining salad dressing on the side for people to add to their personal taste.