In a large pot, combine the chicken broth, carrots, celery, onion, garlic powder, thyme, salt, and black pepper. Bring to a boil over medium-high heat.
Once boiling, reduce the heat and let it simmer for about 10 minutes until the vegetables are tender.
While the broth is simmering, prepare the dumpling batter by whisking together the flour, baking powder, and salt in a mixing bowl.
In another bowl, combine the milk, melted butter, and egg. Pour the wet ingredients into the dry ingredients and stir until just combined.
Add the shredded chicken to the simmering broth, stirring to combine.
Drop spoonfuls of the dumpling batter onto the surface of the broth.
Cover the pot with a lid and let the dumplings cook for about 15 minutes without lifting the lid.
Once the dumplings are cooked through, serve the chicken and dumplings hot in bowls, making sure to include plenty of broth.