Cook the Chicken:
Poach the chicken in a large pot with broth or water for 20-25 minutes. Remove, shred or dice, and set aside.
Prepare the Soup Base:
In the same pot, sauté onions, carrots, and celery in butter or oil until softened.
Add the chicken broth, thyme, and bay leaves. Season with salt and pepper. Bring to a simmer.
Make the Dumplings:
In a mixing bowl, combine flour, baking powder, salt, and pepper. Add milk and melted butter, stirring gently until a sticky batter forms.
Cook the Dumplings:
Drop spoonfuls of dumpling batter into the simmering soup. Cover the pot and let the dumplings steam for 15-20 minutes, until light and fluffy.
Combine and Serve:
Add the shredded chicken back to the soup. Heat through, adjust seasoning, and garnish with fresh parsley before serving.