Consider Celery Root

I adore celery root. Its ivory flesh cooks up earthy and nutty-sweet, with celery‑like undertones (celery root is the same plant species as stalk celery but a different variety grown for its roots) and a light texture. Puree the cooked root with touches of butter and cream, and you’ve got a dish that’s neutral enough to stand in for mashed potatoes yet still offers plenty of personality.

Working with peeled chunks of celery root, I found that braising them in small amounts of water and butter produced the purest taste. And yet I soon found myself in a conundrum: It took 45 minutes for the pieces to turn fully tender, but cooking times longer than 30 minutes produced less celery flavor and more slightly cabbagey sourness. I needed to cook the root as quickly as possible.

Small pieces would soften faster, so I used the food processor to blitz the large, dense chunks into tiny bits. I also added a touch of baking soda to the cooking water, because an alkaline environment would help the root break down. Indeed, after just 15 minutes, the mixture had cooked into a mush that I processed with a pour of heavy cream.

The flavor of the puree was delightful, with a mellow vegetal backbone, but since celery root contains only 5 or 6 percent starch, the consistency was loose. Many recipes call for thickening the puree with potato, and sure enough, half a starchy russet provided just enough body. Finally, a couple savory, herb-forward toppings gave the simple dish holiday pizzazz.