Celery and Celery Root: Puréed

I have never made this purée without someone asking incredulously, “What is this?” This purée is sweet and creamy but still tastes brightly of celery. It also hits one of my key marks of a good recipe: calling for only a handful of ingredients. In the first recipe and first variation, the purée is left plain; in the second and third variations, adding the other flavors to the purée makes it present very differently. Like all purées in this book, it freezes well, so feel free to make a big batch and save some for other quick meals, including thinning the purée with water or stock to make a very fast soup or schmearing on toast for sandwiches.