Season the steak. Pat the steak dry. Mix salt, pepper, chili powder, smoked paprika, and cumin.
Rub with olive oil, then coat evenly with the spice blend. Let it rest at room temperature for 15–20 minutes.
Make the dressing. In a bowl, whisk mayo, sour cream, lime juice, adobo sauce, garlic, honey, cumin, smoked paprika, salt, and pepper. Adjust lime and adobo to taste.
It should be creamy, tangy, and lightly smoky.
Char the corn. If using fresh corn, brush lightly with oil and cook in a hot skillet or on a grill until browned in spots. Slice kernels off the cob. For frozen, toast in a dry skillet until golden.
Cook the steak. Heat a cast-iron skillet or grill over medium-high until very hot.
Cook 3–5 minutes per side for medium-rare, depending on thickness. Aim for an internal temp of 130–135°F (54–57°C).
Rest and slice. Transfer steak to a cutting board and rest 8–10 minutes. Slice thinly against the grain so each bite stays tender.
Assemble the salad base. In a large bowl or platter, layer greens, tomatoes, charred corn, black beans, red onion, and cilantro.
Add avocado just before serving.
Dress and finish. Drizzle some dressing over the salad and toss lightly to coat. Top with warm steak slices, sprinkle with cotija, add tortilla chips for crunch, and serve with lime wedges. Add extra dressing at the table.