In a medium pot, melt the ghee over medium heat and sauté the diced onion, carrots, and celery for 5 minutes until the vegetables are fragrant and slightly softened.
Add the diced chicken breast, chicken bone broth, sea salt, black pepper, and dried thyme to the pot, bringing the mixture to a gentle boil.
Reduce the heat to low and let the soup simmer for 10 minutes to ensure the chicken is cooked through and the flavors meld together.
While the soup simmers, whisk the oat flour, Greek yogurt, and baking powder in a small bowl until a thick, tacky dough forms.
Carefully drop tablespoon-sized portions of the dumpling dough onto the surface of the simmering soup, ensuring they do not overlap.
Place a tight-fitting lid on the pot and steam the dumplings for 5 to 7 minutes until they have puffed up and are firm to the touch.
Ladle the chicken and dumplings into a bowl and garnish with fresh parsley for a bright finish.