The first thing that hits me about celeriac is the smell. It's like the forest floor and a cabbage patch and a grassy field all at once. It is so intensely vegetal. And let's face it: few vegetables can tread the line between root vegetable and garden vegetable with such success. It has the bulk and heartiness of a potato but the lightness and brightness of a very mild celery. It's gorgeous.
And because so few people really eat or make it in the States, it's that smell that immediately takes me to France, and makes me feel like I'm having something ever so special.
This soup was inspired by a vichyssoise, well, if you consider a vichyssoise to be a thick soup of root vegetables and onion rather than exclusively one of potato and leek. The soup is simply celeriac, caramelized shallots, thyme, and vegetable broth, simmered and blended together until it's thick and creamy, even though there's not a drop of cream. In the age old French tradition of stirring grated cheese into hot soups, I serve it with a mound of grated Gruyère to be melted and stirred into the thick and steaming soup.
The result is a hearty soup with the lightness and smell of a garden, punctuated by the slight sweetness of the caramelized shallots and the earthiness of thyme. The Gruyère does magical things, adding that salty nuttiness that I love, and oozing into the soup.
- 1 tablespoon unsalted butter
- 6 small shallots, finely sliced
- 1/4 pound boiling potatoes, peeled and cubed
- 1 3/4 pounds celery root, peeled and cubed
- 2 tablespoons chopped fresh thyme
- Freshly ground black pepper
- 5 cups vegetable broth
- Grated Gruyère, for serving
In a large stockpot, melt the butter over medium heat until frothy. Add the shallots, and cook on medium-low to medium heat until caramelized, about 10 minutes. Keep a cup of water on the side, and add a splash every few minutes to keep the shallots from burning before they are caramelized.
Add the potatoes, celery root, thyme, salt, pepper, and vegetable broth, and bring to a boil over high heat. Cover, and reduce the heat to medium-low, simmering for 30 minutes. Add the contents of the pot to a blender, and carefully purée until smooth. Serve very hot, with a big pile of coarsely grated Gruyère to pile on top and melt into the soup.