- Add the broth and cream, and simmer over medium heat for 30 minutes, adding water if needed.
- In the meantime, sauté the pancetta cubes in a dry pan for 5 minutes, until golden brown.
- Scoop out a few potato and celery chunks.
- Process the remaining soup with a stick blender until creamy. Add the potato and celeriac chunks back to the saucepan.
- Serve the soup hot, topped with the pancetta and garnished with a swirl of heavy cream and thyme.