Heat the ghee in a large pan over medium high heat. Add in the celery and onion and cook until they just begin to soften and brown, about 3-4 minutes. Add into a 7 quart slow cooker
Add all the remaining ingredients up to the chicken and stir until combined. Nestle the chicken into the liquid. Cover and cook on HIGH for 3 hours.
In a medium bowl whisk the tapioca starch and 2 Tbsp of the cooking liquid until smooth. Stir it back into the slow cooker, making sure it's mixed and smooth. Cook another 1 to 2 hours, or until the soup thickens a little bit.
Remove the chicken from the slow cooker and shred. Stir it back into the slow cooker.