Preheat oven to 400 degrees Fahrenheit.
Place the chicken breasts between two pieces of wax paper and use a meat mallet to pound the breasts into an even thickness across, about 1 to 1 ¼ inches.
In a small bowl, combine the chili powder, smoked paprika, cumin, oregano, salt and pepper. Season the chicken breasts on both sides with half of the seasoning mix and reserve the rest.
Heat the canola oil in a large cast iron skillet over medium high heat. (Or use a very heavy-bottomed deep skillet that’s oven-proof.) Add the chicken and cook on one side until well browned, about 3-4 minutes, then flip over and cook for 1–2 minutes on the other side. Remove from the pan. (The chicken will continue cooking later.)
Add the onion to the pan and sauté for 3-4 minutes, then add the garlic and cook for 1 more minute, until fragrant.
Add the black beans, diced tomatoes, corn, green chilies and the reserved seasoning mix. Stir to combine and warm through.
Add the chicken breasts back to the pan and nestle into the bean mixture. Sprinkle the cheese over the entire skillet.
Transfer the skillet to the oven and bake at 400 for 15 minutes, or until the chicken is cooked through. (A meat thermometer should read 165 degrees F.)
Squeeze the fresh lime juice over the skillet and serve the cowboy chicken with any desired toppings.