Place the chicken breasts in a shallow dish and add 1 tablespoon of olive oil, lime juice, minced garlic, ground cumin, chili powder, chopped cilantro, kosher salt, and black pepper. Rub the mixture onto the chicken until well coated, cover, and let it marinate for at least 30 minutes at room temperature or overnight in the refrigerator.

In a small bowl, whisk together the remaining olive oil, lime juice, minced garlic, kosher salt, and black pepper until smooth.

Heat a non-stick frying pan over medium-high heat and add the remaining tablespoon of oil. Once hot, add the marinated chicken and cook for about 5 minutes on each side, or until golden brown and fully cooked through. Allow the chicken to cool slightly before slicing it into strips.

In a large bowl, combine the chopped romaine, halved cherry tomatoes, black beans, corn, thinly sliced red onion, and chopped avocado. Top the salad with sliced chicken and generously drizzle with the prepared dressing.

Toss everything gently to combine, taking care not to mash the avocado. Serve immediately.