Preheat your oven to 350°F (175°C).
In a large skillet, heat the olive oil over medium heat. Add the sliced onion and bell pepper, cooking until softened, about 5-7 minutes.
Stir in the garlic powder, chili powder, cumin, paprika, salt, and pepper. Cook for another minute until fragrant.
In a large mixing bowl, combine the shredded chicken, black beans, corn, salsa, and the sautéed vegetables. Mix well to combine.
Transfer the mixture to a greased 9x13-inch baking dish. Spread it evenly.
Sprinkle the shredded cheddar cheese on top. If using, add the crushed tortilla chips for extra crunch.
Bake in the preheated oven for 25-30 minutes, or until the cheese is melted and bubbly.
Remove from the oven and let it cool for a few minutes. Garnish with fresh cilantro if desired before serving.