Marinate the chicken. In a bowl, mix olive oil, chili powder, cumin, smoked paprika, garlic powder, salt, and pepper. Add the chicken and toss to coat.
Let it rest for 15–30 minutes (or refrigerate up to 8 hours).
Cook the chicken. Grill over medium-high heat 5–7 minutes per side until cooked through, or sear in a skillet with a little oil 6–7 minutes per side. Internal temp should reach 165°F (74°C). Rest 5 minutes, then slice or dice.
Make the dressing. Whisk Greek yogurt, olive oil, lime juice and zest, honey, garlic, chili powder, cumin, and salt.
Add a splash of water to reach a pourable consistency. Taste and adjust salt or lime.
Prep the salad base. In a large bowl, add chopped romaine, black beans, corn, tomatoes, bell pepper, red onion, and cilantro.
Add the avocado. Dice the avocado and gently fold it into the veggies. For extra brightness, squeeze a little lime over it to prevent browning.
Combine. Add the sliced chicken to the salad.
Drizzle with half the dressing and toss lightly to coat. Add more dressing to taste.
Finish and serve. Top with cotija or shredded cheese and tortilla strips if using. Serve immediately with lime wedges on the side.