Preheat the oven to 200℉
Cut bread into 1-inch cubes and spread out on a sheet pan.
Toast the bread cubes for 20 minutes, or until they are slightly crunchy.
Allow the bread cubes to cool.
In a medium skillet, sauté the onions and celery in the butter until tender.
Add the poultry seasoning, salt and pepper.
In a large bowl, combine the dried bread cubes and seasoned onion and celery.
Pour half of the chicken broth into the bowl, stirring gently.
Whisk the egg and gently stir into the mixing bowl.
Add finely chopped parsley and rosemary.
Slowly add chicken broth until the bread cubes are wet but not soaked.
Grease a large crock pot and pour in stuffing mixture.
Set on low for 4 hours. Fluff with a fork every hour until done.