Often, celery root (celeriac) is grated and served raw in a salad (celeri remoulade), made into soup or, pureed or cubed, put to use as a side dish. It is a great vegetable that deserves to be better known in this country, but sadly it is not commonly seen in supermarkets.
Farmers markets are another story, and from midsummer well into fall and even winter, celery root can easily be found, with its deeply furrowed root ends that remind me of a Shar-Pei dog’s (or W.H. Auden’s) no less deeply furrowed face.
Dining out a couple of years ago, Jackie and I were served a dish that included a thickish slab of celery root, which had been slowly poached in a butter-water emulsion. This was an eye-opener in more than one way: First, the vegetable tasted both of itself and divinely buttery; secondly, its texture was delightful — tender, but with a density that demanded cutting it with a knife; and finally, it was the unexpected star of that dish, to the extent that I have no recollection of what the “main” ingredient was. Fish? Poultry? Could have been scrapple for all I remember. (Actually, that may not be such a bad idea.)
From this, I drew the conclusion that plain celery root could be served on its own as a first course, and soon after our restaurant meal, I prepared it just that way. I didn’t try to use the same cooking technique: The few times I’ve tried poaching in butter emulsions they’ve broken on me.
Instead, I “braised” thick slices of peeled celery root in a covered pan with a lump of butter, a little water, a squeeze of lemon juice and salt, turning them from time to time and making sure the water didn’t completely evaporate. Then I put one slice on each diner’s plate, sprinkled it with crunchy sea salt and garnished it with grated lemon zest. The dish was a big hit; people who’d never eaten celery root before were smitten, and those who were already familiar with it had certainly never eaten it just sitting on a plate like a steak.
More recently, having come upon some particularly fragrant and firm celery root in our local farmers market and planning a dinner party with a copious main dish of roasted pork belly, I thought a revisit of this meatless first course was in order. The thing was, one of the guests had already had the simple version I just described, and I thought I’d better update it.
First, a simple cosmetic change: Instead of a puck-shaped slice of celery, I just halved the deeply peeled roots, forming hemispheres (which I placed in water acidulated with lemon juice to keep them from turning brown before cooking). These would look like little domes on the plate. Note that the celery roots we get in our market are not that big: We’re talking 3 inches in diameter once they’ve been peeled. If yours are more the size of soccer balls, go back to Plan A and use 1 1/2-inch slices, cut in half if necessary to make reasonable portions (because of this root’s uniformity, you probably don’t want a huge quantity).
Secondly, I thought about a sauce. The key flavor in classic celeri remoulade is mustard. Not long ago, we had a nice crab cake at Central Michel Richard. It contained whole mustard seeds, which, if I remember correctly, had been soaked to soften them. They added both mustardy sparkle and a gentle crunch as they popped when we chewed them. Just what I wanted for my sauce. So, a day in advance, I soaked a few tablespoons of whole yellow mustard seeds in a mixture of water and lemon juice, lightly sugared and salted (brown/black mustard seeds would be fine too — and would look like caviar to boot). Within a few hours they had swelled and softened: Just right for a sauce.
I cooked half a dozen celery root domes just as I had before and dished them up onto soup plates. (They took about 15 minutes over medium-low heat — keep checking with a thin-bladed knife or skewer until they’re tender but not too soft.) You can do this an hour in advance and reheat them if you like. They had left lovely, buttery juices in the pan, and to these, I added perhaps 2/3 cup of cream, a tablespoon of Dijon mustard, a couple of tablespoons of soaked mustard seeds (drained) and the juice of half a lemon. After checking for salt, I spooned some of this sauce over each portion, and that was that.
Admittedly, the simplicity of the original version had its appeal, but those mustard seeds lifted the newer dish into a higher realm. While you can still get beautiful, sound celery root in the market, why not try both?