In a large bowl combine the onion, celery, parsley, Herbs de Provencal, garlic powder, green onions, ham, cheese, stuffing and 1/2 cup chicken broth. Mix well
Scoop 1/4 cup stuffing mix and place in the center of chicken breast. Fold in sides, then roll making sure to tuck in any stuffing as you go, secure with a toothpick.
Continue rolling until all are chicken breast are filled. Place any remaining stuffing in bottom of a foil lined baking pan, place chicken on top of any remaining stuffing. Bake for 35-40 minutes or until chicken juices run clear.
While chicken is cooking make a quick pan sauce to top chicken after cooking. Heat a saucepan over medium heat, melt butter, add flour, continuously stir to form a roux, when slightly golden sprinkle with poultry seasoning and salt/pepper to taste, slowly add remaining broth, bring to boil, then reduce heat to simmer until sauce reduces by almost half and thickens.
Spoon sauce over the chicken and serve immediately
Notes
Pound evenly: Pound chicken breasts to an even thickness so they roll easily and cook at the same rate. This helps prevent dry chicken.
Don’t overfill: About ¼ cup stuffing per breast is ideal. Overfilling makes rolling harder and causes the filling to leak.
Secure well: Use 1–2 toothpicks per breast and tuck the ends in as you roll to keep the stuffing inside while baking.
Bake to doneness, not time: Chicken is done when juices run clear or the internal temperature reaches 165°F.
Sauce thickness: If the pan sauce is too thin, simmer a few extra minutes. If too thick, whisk in a splash of broth.
Make ahead: Stuff the chicken up to 24 hours in advance and refrigerate. Bake just before serving.
Storage: Store leftovers in an airtight container in the refrigerator for up to 3–4 days.
Freezing: Fully cooked stuffed chicken can be frozen up to 2 months. Thaw overnight and reheat gently.