01 - Combine chicken thighs, onion, carrots, celery, garlic, thyme, parsley, black pepper, salt, and chicken broth in the slow cooker. Stir thoroughly to distribute seasonings evenly.
02 - Cover and cook on low heat for 5 hours until chicken becomes very tender and vegetables are softened.
03 - Remove chicken from the slow cooker. Using two forks, shred the meat into bite-sized pieces. Return shredded chicken to the pot.
04 - Stir in heavy cream and butter pieces until butter melts and the broth becomes creamy and rich.
05 - In a medium bowl, whisk together flour, baking powder, and salt. Add melted butter and milk, stirring until just combined. The dough should be thick and slightly sticky. Fold in fresh parsley. Do not overmix.
06 - Drop rounded spoonfuls of dough (approximately 2 tablespoons each) onto the surface of the hot stew. Space them evenly to allow for expansion.
07 - Cover and cook on high heat for 45 to 60 minutes until dumplings are puffed, firm to the touch, and cooked through.
08 - Taste the broth and adjust seasoning with additional salt or pepper if desired. Serve hot, garnished with extra fresh parsley.