Preheat and prep: Heat your oven to 375°F (190°C). Lightly coat a 9x13-inch baking dish with cooking spray.
Sauté the veggies: Warm olive oil in a large skillet over medium heat. Add onion and bell pepper with a pinch of salt.
Cook 4–5 minutes until softened.
Build the flavor base: Stir in chili powder, cumin, smoked paprika, garlic powder, and onion powder. Cook 30 seconds, stirring, until fragrant.
Mix the wet ingredients: In a bowl, whisk together Greek yogurt and chicken broth until smooth. This keeps the casserole moist and creamy without heavy sauces.
Combine the filling: In a large mixing bowl, add shredded chicken, cooked brown rice, black beans, corn, sautéed veggies, salsa, and drained tomatoes with green chiles.
Pour in the yogurt-broth mixture. Season with salt and pepper. Stir until evenly combined.
Layer and top: Spread the mixture evenly in the prepared dish.
Sprinkle cheese across the top in an even layer.
Bake: Cover loosely with foil and bake for 15 minutes. Remove foil and bake another 10–12 minutes, until the cheese is melted and the edges are bubbling.
Rest and garnish: Let it rest 5–10 minutes so it sets slightly. Top with cilantro, green onions, and a squeeze of lime if you like.
Serve: Spoon into bowls and add avocado slices or a light hot sauce drizzle for extra pop.