- Cut celery and potatoes into one inch chunks.
- Add to soup pot with the chicken broth and chicken breasts. Bring to a boil. Reduce heat, cover and simmer 25-30 minutes or until potatoes are soft and the chicken is cooked through. Remove chicken breasts from pot and set aside to cool. Cut chicken into 1/2 inch (1.5 cm) chunks and reserve.
- Puree soup using an immersion blender.
- Melt butter in saucepan. Add diced onion and sauté until translucent. Add finely minced celery and celery seed and sauté until tender and fragrant - about 5 minutes.
- Whisk milk, sour cream, reserved cooked chicken, salt, white pepper and dried tarragon into soup about 10 minutes before serving. The amount of salt needed will depend on the saltiness of your broth. Serve immediately as it is best not over-cooked. Garnish each bowl with a sprig of fresh celery.
Use your fingers to crumble dried herbs into the soup. This helps release volatile oils which heighten flavour.
For additional fibre, make this soup with the skin on the potatoes. The soup is smoother without the peels. You decide!