Preheat oven to 300°F.
In a large dutch oven over medium heat, melt butter. Sauté diced onions, diced carrots, and diced celery for 7 minutes.
Stir in minced garlic and sauté 1 minute.
Sprinkle in 7 tablespoons flour and stir mixture for 2 minutes.
Gradually whisk in broth and milk until soup is smooth.
Stir in cut chicken, salt, and pepper.
Cover with lid. Cook in oven for 30 minutes.
To make the dumplings, whisk together flour, 1 tablespoon baking powder, garlic powder, pepper, salt, and parsley.
Stir in warm milk and butter until dough comes together.
Remove chicken soup from oven. Using two spoons, form golf size balls of dough and place on top of soup evenly; about 18 balls.
Simmer on stovetop for 15 minutes covered.
Broil dumplings on high in oven for 5-10 minutes if desired.