Heat the olive oil in a large skillet over medium-high heat. Add the chicken pieces and cook until browned on all sides, about 5-7 minutes. Remove chicken from the skillet and set aside.
Add the chopped onion and bell peppers to the same skillet. Cook, stirring occasionally, until softened, about 5-7 minutes. Add the minced garlic and cook for another minute until fragrant.
Stir in the rinsed black beans, drained corn, and the can of diced tomatoes with green chilies. Add the chili powder, cumin, cayenne pepper (if using), salt, and pepper. Bring the mixture to a simmer.
Return the browned chicken to the skillet. Stir everything together and let it simmer for 10-15 minutes, or until the chicken is cooked through and the sauce has thickened slightly.
Taste and adjust seasonings as needed. Serve hot.