Preheat your grill or a grill pan over medium-high heat.
In a small bowl, mix together the garlic powder, onion powder, cumin, paprika, salt, and black pepper. Rub this spice mixture evenly over both sides of the chicken breasts.
In another bowl, whisk together the lime juice and olive oil. Marinate the seasoned chicken in this mixture for at least 15 minutes, or up to 2 hours in the refrigerator for more flavor.
While the chicken is marinating, prepare the corn, black beans, and diced tomatoes in a large bowl. Mix them together and set aside.
Grill the marinated chicken for about 6-7 minutes on each side, or until the internal temperature reaches 165°F.
During the last few minutes of grilling, top each chicken breast with the corn, black bean, and tomato mixture, then sprinkle with shredded cheese. Close the grill lid to melt the cheese.
Once cooked, remove the chicken from the grill and let it rest for 5 minutes. Garnish with chopped cilantro and serve with lime wedges.
Notes
For a spicier kick, add diced jalapeños to the corn and bean mixture.
Serve with a side of rice or tortilla chips for a complete meal.