Celeriac, aka celery root, is the bulbous root cousin of stalk celery. The ugly, knobby exterior hides a flesh with the texture of a potato (though much less starchy) and the flavor of mild celery. Because of this, it makes a great base for soups, stews, roasts, and mashes. It can also be eaten raw. One of the traditional French ways of eating it is to make a delicious slaw called Celeriac Remoulade–shredded celery root with lemon juice, mayonnaise, dijon mustard, and black pepper. No matter what you do with your celeriac, you’ll want to slice off the rough outer skin before using it (but save clean skin and stems for soup stock!)
One go-to winter vegetable recipe that works especially well with celeriac is to make “scalloped fill in the blank.” The basic technique is to slice root vegetables and/or winter squash into thin rounds, layer the rounds in a casserole or skillet, then bake until the top and edges get crispy. Fancier versions include adding buttery bread crumbs and cheese to the top to make it a gratin or a creamy béchamel sauce. Any combination of root vegetables will do. This time, I kept it simple with potatoes and celeriac, but feel free to throw in parsnips, turnips, sweet potatoes, butternut squash, carrots, or any fresh herbs you have.
Scalloped Celeriac and PotatoesStart by cutting off the skin of 1 celeriac bulb. Now slice it very thinly using a knife or a mandoline. Wash 1 pound gold potatoes and slice them thinly as well (no need to peel). Preheat oven to 400 degrees. Coat the bottom and sides of an oven-proof skillet with vegetable oil or cooking spray. Over medium heat, melt 1 tablespoon butter in the skillet. Arrange half of the potatoes in concentric circles on top of the butter. Repeat with celeriac, and then with remaining potatoes. Smoosh the whole arrangement down so that it compacts a bit. Sprinkle with salt and pepper. Cover skillet and cook on medium-low heat for about 25 minutes until the bottom of the first layer of potatoes starts to brown. Drizzle with 1 more tablespoon melted butter and bake in the hot oven uncovered for about 30 minutes, until vegetables are very tender and starting to crisp on the top. Cut into wedges and serve, making sure to get the crispy brown potatoes from the bottom layer in each serving.