Melt margarine, add water, pour over croutons and mix. Put half in greased 9x13 pan.
Mix turkey, celery, onion and mayonnaise. Pour over crouton mixture in pan.
Cover with remaining half of croutons. Beat egg with milk, pour over above
and refrigerate overnight. Next day, pour mushroom soup on top. Bake 45
minutes at 325°. Cover with cheese and bake 10 minutes longer.