Spray a 6- to 8-quart Crockot or slow cooker with cooking oil spray. Oval works best.
Melt butter in a very large microwave-safe bowl. Otherwise, melt it in a small bowl and pour into the very large bowl. It can also be melted in a small saucepan on the stovetop.
Add the onion, celery, bell pepper seasoning blend to the butter. Move this mixture to one side of the bowl. Lightly beat the eggs on the other side of the bowl, then stir it all together. Add the cream of chicken soup, poultry seasoning, and stir well.
Add the package of dried cornbread “stuffing” and the herb seasoned dried cubes of bread to the mixture. Stir just until combined. Pour the chicken broth over everything and stir gently just until combined.
This is when I pull the chicken from the rotisserie so the mixture can sit 5 minutes. Add the pieces of chicken and stir gently just until combined.
Pour the dressing mixture into the greased Crockpot. Cover with lid and cook on LOW for 8 hours. It can be cooked on HIGH for 4 hours but I recommend the lower setting to have time to cook the vegetables and hydrate the dried cornbread and bread cubes and avoid overdone edges.
To speed up the cooking time, you can start the slow cooker on HIGH for the first 2 hours, then reduce it to LOW for 3 hours and that shaves off 3 hours.