Root vegetables are available when other green vegetables are not, and this one is economical, has longevity in the refrigerator, and has a very pronounced, clean flavor. I like celery root cooked as well as raw in salads. And I love it in this soup!
- 8 cups Chicken Stock, preferably homemade (recipe)
- 2 tablespoons unsalted butter
- 2 tablespoons extra-virgin olive oil
- 1 cup chopped onion
- 4 garlic cloves, peeled and crushed
- 2 tablespoons all-purpose flour
- 2 pounds celery root, peeled and chunked
- Kosher salt to taste
Bring the chicken stock to a simmer in a saucepan.
In a soup pot, melt the butter in the olive oil over medium heat. When the butter is melted, add the onion and garlic, and cook until softened, about 5 minutes. Sprinkle in the flour, and stir to form a smooth roux with no clumps of flour. Cook, without browning the flour, for a few minutes to remove the raw flour smell and taste.
Slowly add the hot chicken stock, whisking to combine it with the roux. Add the celery root, and season with salt. Bring to a simmer, and cook until the celery root is very tender, about 30 to 40 minutes. Purée in batches in a blender, or right in the pot with an immersion blender. Return to a simmer and serve.