Florentine Stuffed Chicken

Preheat oven to 350 degrees F (175 degrees C).

In a medium bowl combine the spinach Parmesan cheese and onion and mix thoroughly. Stuff the cavity of each chicken breast with 1/4 of the mixture. (NOTE: Bone-in split breasts usually have a little cavity; if one is not naturally present use a sharp knife to make a slit in the side of the breast.)

Lay stuffed breasts in a 9x13 inch baking dish and cover with the sauce.

Bake at 350 degrees F (175 degrees C) for about 35 minutes or until chicken is cooked through and tender; sprinkle with mozzarella cheese and bake another 5 minutes until cheese is melted.