Preheat and prep: Heat your oven to 400°F (200°C). Lightly coat a 9x13-inch baking dish with cooking spray.
Sauté the veggies: Warm the olive oil in a skillet over medium heat. Add the onion and bell pepper; cook 4–5 minutes until softened.
Stir in the garlic and cook 30 seconds more, just until fragrant.
Build the sauce base: Add the salsa, diced tomatoes, chili powder, cumin, smoked paprika, oregano, salt, and pepper to the skillet. Stir and let it bubble for 2–3 minutes to marry the flavors. Taste and adjust seasoning.
Fold in beans and corn: Stir the black beans and corn into the sauce.
Turn off the heat.
Layer the chicken: Arrange the chicken slices in a single layer in the baking dish. Lightly season both sides with a pinch of salt and pepper. You want even coverage so everything cooks at the same rate.
Add the veggie mixture: Spoon the sauce, beans, and corn evenly over the chicken.
Make sure every piece is covered to keep it moist.
Bake: Place the dish on the middle rack and bake for 20–25 minutes, or until the chicken reaches an internal temperature of 165°F and is no longer pink.
Add cheese: Sprinkle the reduced-fat cheese evenly over the top. Return to the oven for 3–5 minutes, just until melted and bubbly.
Rest and garnish: Let the bake rest for 5 minutes. Top with chopped cilantro and a squeeze of lime.
Serve with a dollop of Greek yogurt if you like a creamy contrast.