Prepare biscuits (enough to make 4 cups crumbled), and one 8x8 inch pan cornbread according to package directions. Cool and crumble.
Preheat oven to 350 degrees F (175 degrees C).
In a small pot, combine onion, celery, margarine and chicken broth. Bring to boil and cook vegetables until tender.
In a 2-quart casserole dish, combine 4 cups crumbled cornbread, 4 cups biscuit crumbs, salt, pepper, sausage, chopped eggs and sage. Pour broth and vegetables over bread mixture, and stir until combined.