Preheat the grill to medium-high heat. In a small bowl, mix together olive oil, chili powder, cumin, garlic powder, onion powder, salt, and pepper. Rub the spice mixture all over the chicken breasts.
Place the chicken on the grill and cook for about 6-7 minutes on each side, or until the internal temperature reaches 165°F. Remove from the grill and let it rest for 5 minutes before slicing.
In a large bowl, combine the salad greens, cherry tomatoes, corn, avocado, black beans, red onion, and cilantro.
Slice the grilled chicken and place it on top of the salad. Drizzle with your favorite dressing or a squeeze of lime juice.
Serve immediately with lime wedges on the side.