Prepare cornbread and biscuits a day ahead of time.
Preheat oven to 350 ℉.
Spray large roasting pan with non-stick coating.
Crumble cornbread and biscuits to a fine texture, keeping the ratio of cornbread to biscuits 3:1.
Add onion, celery, eggs, evaporated milk, sage, and salt and pepper.
Mix well, and add 2 to 3 boxes of the broth to reach a soupy consistency.
Place covered roaster in oven for an hour to an hour and 20 minutes and then every 15 minutes, check consistency of the dressing, adding additional broth as necessary. Be sure to scrape sides and bottom or roaster to prevent any of the dressing from becoming too dry. The finished dressing should have the consistency of mashed potatoes.
Prepare cornbread and biscuits a day ahead of time and allow to set out until ready to use.For the cornbread and biscuit mixture, use approximately 75% cornbread and 25% biscuits.Onion and celery should be of approximately equal parts, for example, a cup of each.This Southern Cornbread Dressing Recipe freezes well for later use. Simply thaw, reheat in oven, and reconstitute with additional broth as necessary.