Celery rarely assumes a starring role in soups, though it's commonly added as an aromatic, so this recipe is a tad different because it calls for 6 cups of the vegetable. Apples mellow the celery's herbal quality and add a hint of sweetness.
This is a delicious soup for a cold night — and a nutritious one, too. Enjoy!
Melt the butter in a large saucepan over medium heat. Add the leeks and celery and cook, stirring frequently, until the vegetables begin to soften, about 4 minutes. Add the peeled, diced apples, 6 cups of the chicken stock, and the apple juice, and raise the heat to high. Cook until the mixture reaches a simmer, then reduce the heat to medium-low, cover the pan, and cook until the mixture is soft and tender, about 45 minutes.
Purée the soup in a blender or food processor. Return the soup to the pan and add the heavy cream, if using, reheating the soup over low heat until hot. If you prefer not to use the cream, and if the soup is very thick, thin it with some of the reserved stock or with some hot water.
To serve, divide the bisque among 4 bowls. Garnish each serving with a sprinkling of minced celery leaves and a tablespoon of diced, unpeeled apples.