Use rotisserie chicken to save time. Pepperidge Farm-style cornbread stuffing (fine crumb mix) works best here; avoid large bread cubes. If you prefer, swap the cream of celery for cream of mushroom. For make-ahead, assemble, cover, and refrigerate up to 24 hours; add 5–10 minutes to the covered bake time. Leftovers keep 3–4 days in the fridge; reheat covered at 325°F until warmed through or microwave in portions.