Melt the ghee in a large pot over medium heat and sauté the diced onion, carrots, and celery until the vegetables are slightly softened and fragrant.
Stir in the minced garlic and cook for one minute, then pour in the chicken bone broth and bring the mixture to a gentle simmer.
Add the diced chicken breast to the pot and continue to simmer for about 5 minutes while you prepare the dumpling dough.
In a small mixing bowl, whisk together the cassava flour, baking powder, dried thyme, and a pinch of salt.
Stir in 2 tablespoons of the warm broth from the pot into the flour mixture until a thick, tacky dough forms.
Drop rounded tablespoons of the dough into the simmering broth, then cover the pot with a tight-fitting lid.
Steam the dumplings for 8 to 10 minutes without lifting the lid until they are puffed and cooked through.
Season with the remaining salt and black pepper, then garnish with fresh parsley before serving in deep bowls.