Preheat the oven to 350F degrees. Grease or butter a 9x13 casserole dish.
Melt 4 tablespoons butter in a microwave safe dish. Set aside to cool while you prepare the remaining ingredients.
Combine the celery, onion, apple, salt, sage, rosemary, thyme, and parsley in a large bowl. Set aside.
Brown the Italian sausage in a large nonstick skillet over medium heat.
Remove the sausage from the pan and set aside. Leave the fat from the sausage in the pan to saute the vegetables. Add 2 tablespoons of butter to the fat in the pan.
Add the celery mix to the warm pan with the fat. Cook over medium heat until softened, about 10 minutes.
Combine the cooked vegetables, sausage and cornbread chunks together. Stir gently so as to keep the cornbread chunks intact. Spread the cornbread mixture into your prepared casserole dish.
In a medium sized bowl, combine the eggs, chicken broth and remaining 4 Tablespoons of melted butter. Whisk together until smooth. Pour over the cornbread mixture in the casserole dish. Do not stir.
Bake for 30 minutes uncovered, then cover with foil and bake an additional 30 minutes.