This soup is smooth and delicate, and its elegant celery leaf garnish makes it a perfect first course for a dinner party. Adding celery root (a relative of celery) imbues the soup with even deeper celery flavor.
In a 4-quart pot, melt the butter over medium heat. Add the celery, onion, and a generous pinch of salt. Cook until tender and just beginning to color, 6 to 8 minutes. Add the celery root and stir to coat with the butter. Pour in the chicken broth, and then add the thyme, bay leaf, and 1/2 tsp. salt. Bring to a boil; then reduce the heat and simmer until the vegetables are very tender, about 15 minutes. Discard the thyme sprigs and bay leaf and purée the soup in a blender until smooth. Pass the soup through a medium-fine sieve and transfer to a clean pot. Bring the soup back up to a simmer, whisk in the crème fraîche, and season to taste with salt and pepper. Keep hot.
Heat 1/2 inch of canola oil in a 1-quart pot over medium-high heat. Add the celery leaves and cook until crisp, 1 to 2 minutes. Using a slotted spoon, transfer the celery leaves to a plate lined with paper towels.
Ladle the soup into bowls and top with the celery leaves.
nutrition information (per serving):
Photo: Scott Phillips