Soak cauliflower, head down, one hour in cold water to
cover; cook in boiling salted water twenty minutes. Reserve
one-half flowerets, and rub remaining cauliflower through
sieve. Cook onion, celery, and bay leaf in butter five minutes.
Remove bay leaf, then add flour, and stir into hot
stock; add cauliflower and milk. Season with salt and
pepper; then strain, add flowerets, and reheat.