1. Season the chicken with the black pepper and oregano.
2. Heat the oil in a 12-inch nonstick skillet over medium-high heat. Add the chicken and cook for 10 minutes or until it's well browned on both sides.
3. Stir the sauce in the skillet and heat to a boil. Reduce the heat to low. Cover and cook for 5 minutes.
4. Uncover the skillet. Stir in the beans and spinach and cook for 5 minutes or until the chicken is cooked through.