Place the chicken thighs in the slow cooker. Add the chicken broth, honey, Dijon mustard, onion, carrots, celery, garlic, thyme, salt, and black pepper. Stir to combine the sauce ingredients.
Cover and cook on low for 6 hours until the chicken is tender and shreds easily.
Shred the chicken directly in the slow cooker using two forks. Stir the mixture well.
In a mixing bowl, combine the flour, baking powder, and salt. Stir in the milk and melted butter until a soft dough forms.
Drop spoonfuls of the dough onto the surface of the hot chicken mixture. Cover and cook on high for 1 hour until the dumplings are cooked through and no longer doughy in the center.
Sprinkle with chopped parsley before serving.