Heat the avocado oil in a large stock pot or Dutch oven over medium heat. Add the onion and saute, stirring occasionally, until transluscent, about 5 to 8 minutes. Add the carrots, parsnips, celery, and garlic and continue sauteeing, stirring occasionally, until vegetables are softened but still al dente, about 3 to 5 minutes.
Add the chopped chicken and cook just long enough to brown the meat, about 2 to 3 minutes.
Add the remaining ingredients, stir well and cover. Cook at a gentle simmer, stirring occasionally, for at least 30 minutes (ideally one hour). Taste soup for flavor and add more sea salt if desired. Serve and enjoy!
*Omit onion and garlic to make Low-FODMAP