Prepare the ingredients: Chop the chicken, vegetables, and herbs.
Heat olive oil in a large pot over medium heat and sauté onions, carrots, and celery until tender.
Add garlic and thyme, cooking for another minute until fragrant.
Pour in the chicken broth and bring to a simmer.
Add the chicken thighs to the pot and simmer for 20-25 minutes, until they are fully cooked.
Remove the chicken from the pot, shred it, and return it to the pot.
In a bowl, combine flour, baking powder, and salt. In another bowl, mix melted butter and milk, then combine with the dry ingredients to form the dumpling dough.
Scoop spoonfuls of the dumpling mixture into the simmering broth.
Cover and simmer without lifting the lid for 15 minutes to allow dumplings to cook through.
Season with salt and pepper to taste before serving.
Serve hot, garnished with fresh herbs if desired.