Celery root is the ugly duckling of the farmers' market. Gnarled, twisted, and bumpy, the mass of tendril-like roots can usually be found caked with dirt. Someone unfamiliar with this vegetable would surely reach for a gorgeous persimmon, a wine-colored radicchio, or even a mysterious kohlrabi before picking up a celery root. But looks can be deceiving. This underrated root's homely appearance belies its inner beauty.
Celery root is not, as the name implies, the root of a celery plant. Apium graveolens var. rapaceum is a special variety of celery, cultivated for its swollen junction between stem and root. It grows half above ground and half below. A native of the Mediterranean, celery root is harvested in the fall and keeps well through the winter in mild climates. Celery root, sometimes called celeriac, is most popular in France, where it is commonly eaten raw in a mustard-and-mayonnaise-coated slaw called céleri rémoulade. When the vegetable is raw, it has a crisp, crunchy texture, but when cooked, it becomes lusciously smooth. Its flavor is like that of celery and parsley -- fresh, clean, and bright -- only more concentrated, more desirable, and with a subtle earthy note.
Select small and firm celery roots. The larger ones tend to be porous in the center. Look for newly harvested bulbs, which will show off their youth with a tuft of vibrant leaves and stems. When you get home from the market, snap off these few short stalks and refrigerate the bulb, loosely wrapped in plastic, for up to 3 weeks. To prepare the celery root for cooking, start by cutting a slice off the top and bottom. Continue slicing away all roots, hairy protuberances, and tough brown skin, until you are left with a clean, smooth, porcelain-like polyhedron. Underneath the celery root's outward tangle of roots you will find a beautiful, tasty surprise.
Steak with Smashed Potatoes and Celery Root
This is one of my favorite romantic dinners; it is ideal for sharing on a winter night.
1 10-ounce ribeye steak
1 small (about ¾ pound) celery root
1½ pounds Yukon Gold potatoes
1 clove garlic, peeled
½ cup milk or cream, optional
2½ tablespoons unsalted butter
1½ tablespoons olive oil
2 teaspoons fresh rosemary leaves
1½ tablespoons chopped chives, for serving
Kosher salt and freshly ground black pepper
Remove the steak from the fridge so that it can warm to room temperature. Using a paper towel, thoroughly pat the steak dry. Season it generously with salt and pepper. It may seem like a lot of salt, but ¼ teaspoon per side is about right.
While the steak warms up, make the smashed potatoes and celery root. Begin by peeling the celery root (as described in the article above) and the potatoes. Cut them both into 1-inch pieces and place them in a medium pot. Cover with water. Add 1 teaspoon salt and the garlic. Bring the water to a boil. Cook the potatoes and celery root for 15 minutes. Drain, reserving the cooking water.
Return the vegetables to the pot over low heat, then mash them. Any utensil will get the job done, even a wooden spoon, but you can press the vegetables through a ricer or the large holes of a food mill for a smooth purée. Stir in ½ cup cooking water, milk, or cream, depending on how rich you would like the mash to be. Add 2 tablespoons butter, a pinch of salt, and a few grinds of pepper. (The smashed potatoes and celery root can be made up to 2 hours in advance and reheated just before serving.)
When you are ready to cook the steak, heat a cast-iron skillet over medium-high for several minutes. The pan should be very hot. Swirl in the olive oil and let it heat up for 30 seconds, or until it begins to smoke. Place the steak in the center of the skillet. Cook it for 4 minutes, flip it over, and cook it for another 2 minutes. For medium-rare, the internal temperature of the steak should be about 130°F.
Transfer the steak to a plate. Set the remaining ½ tablespoon of butter on top of the steak, and sprinkle it with the rosemary leaves. When the butter has melted fully, slice the steak crosswise at a slight angle.
To serve, mound some of the smashed potatoes and celery root in the center of a warm plate. Sprinkle the chives, and place a few slices of steak on top of the mash.