Preheat the oven to 375°F (190°C).
In a medium bowl, combine the drained white corn, drained and rinsed black beans, diced green chiles, chopped cilantro, and chopped red onion; stir to mix evenly.
Season both sides of the chicken breasts with the salt, cumin, and garlic powder.
Place the seasoned chicken breasts flat in a large baking dish.
Spoon the corn and bean mixture evenly over the chicken, then sprinkle the shredded cheddar cheese on top.
Bake in the preheated oven for 35–45 minutes, or until the chicken reaches 165°F (74°C) internal temperature and the cheese is melted and bubbling.
Remove from the oven, squeeze the lime juice over the top, and garnish with additional cilantro if desired before serving.