This is an incredibly delicious pairing and, to my taste, the best of the purees. Serve with Broiled Marinated Duck Breasts and deep-fried celery leaves.
Using a stainless-steel knife to prevent discoloration, peel the celery root and cut it into chunks. In a large nonreactive saucepan, simmer the celery root in the milk for 10 minutes.
Meanwhile, peel, core, and quarter the apples. Add to the celery root and simmer together for 10 minutes longer, or until celery root is tender; drain.