2 celery roots (1 pound each), peeled and cut into 1/2-inch pieces
2 cups heavy cream
1 cup water
Salt and freshly ground pepper
In a large saucepan, combine the celery roots with the cream and water and bring to a boil. Cover and simmer over moderately low heat until tender, about 30 minutes. Uncover and cook over high heat until the cream is thickened and reduced by half, about 8 minutes.
Transfer the contents of the pan to a food processor and puree until smooth. Season with salt and pepper. Return the puree to the saucepan and cook over moderate heat, stirring constantly, until warmed through. Serve at once.
The celery root puree can be refrigerated overnight. Reheat gently.