Season the chicken with the salt and black pepper, and coat with flour.
Heat oil in a skillet set over medium-high heat. Add chicken and cook until browned on both sides. Remove chicken from the skillet. Add the onion to the skillet and cook for 5 minutes, stirring occasionally.
Stir in the sauce, spinach, and artichokes. Return the chicken to the skillet. Reduce the heat to medium-low. Cover and cook for 10 minutes, until the spinach is wilted and the chicken is cooked through. Top with cheese before serving.