In a very large bowl, mix the crumbled cornbread and biscuits. Pour chicken stock over the bread mixture, stirring to combine. Set aside.
In a medium saute pan, melt the butter over medium heat. Add the celery and onion and saute until the celery is softened and the onions are golden, 5-7 minutes. Add sauteed vegetables, poultry seasoning, salt and pepper to the bread mixture, stirring well to combine. Stir in the eggs.
Pour mixture into a greased lasagna pan (a 9x13" pan will work, too, but it will be very full). Bake at 350 degrees for 40-45 minutes, or until top is golden.