Melt butter in casserole dish. Pour melted butter into a bowl.
Add cream of mushroom soup, cream of chicken soup, chicken broth, celery, onion, egg, sage, S&P.
In buttered casserole dish, place a layer of cornbread mix, a layer of chicken, a layer of soup mix, a layer of cornbread mix (top layer should be cornbread mix).
Bake at 350 degrees for 45 minutes. Let cool to room temperature before freezing.
To reheat: Thaw overnight. Remove lid and reheat.