- 1 cup vegetable stock or broth
- 1 celery root (celeriac), about 1 pound, peeled and diced
- 1/4 cup sour cream
- 1 teaspoon Dijon mustard
- 1/4 teaspoon salt
- 1/4 teaspoon freshly ground black pepper
- 2 teaspoons fresh thyme leaves
In a large saucepan, bring the stock to a boil over high heat. Stir in the celery root. When the stock returns to a boil, reduce the heat to low. Cover and simmer, stirring occasionally, until the celery root is tender, 10 to 12 minutes.
Using a slotted spoon, transfer to a bowl, cover and keep warm. Raise the heat under the saucepan to high and bring the cooking liquid to a boil. Cook, uncovered, until reduced to 1 tablespoon, about 5 minutes. Remove from the heat and whisk in the sour cream, mustard, salt and pepper. Add the celery root and thyme to the sauce and stir over medium heat until heated through. Transfer to a warmed serving dish and serve immediately.