Crumble the muffins and biscuits into small pieces.
Using a small amount of butter or olive oil, sauté the celery and onions until tender.
Combine the eggs, salt, pepper, chicken broth, celery and onions with the muffin and biscuit mixture and stir. The consistency at this stage should be similar to thick oatmeal. Add more chicken broth if needed.
Bake in a large greased casserole dish at 350° for 40-45 minutes, or until the top turns golden brown.