Preheat a large non-stick grill pan over medium-high heat for about 5 minutes.

In a small bowl, combine 1 tablespoon of olive oil, 1 teaspoon of chili powder, 1 teaspoon of ground cumin, and ½ teaspoon of garlic powder. Add salt and pepper to taste, and whisk until well blended.

Brush the seasoning mixture generously over both sides of the chicken breasts. Let them rest while you check the pan temperature.

Place the seasoned chicken breasts on the grill and cook for about 6-7 minutes on each side, or until cooked through.

Remove the chicken from the pan and let it rest for 5 minutes before slicing it into strips.

In a large bowl, combine the rinsed black beans, corn, red bell pepper, avocado, red onion, cilantro, romaine lettuce, and cherry tomatoes. Toss gently.

In another bowl, mix together the Greek yogurt, lime juice, and salt and pepper. Whisk until smooth.

Drizzle the dressing over the salad ingredients and toss gently until evenly coated.

Top the salad with the sliced grilled chicken and serve immediately or refrigerate for up to 2 days.