01 - Place chicken, diced onion, sliced carrots, sliced celery, minced garlic, dried thyme, dried parsley, dried rosemary, salt, and black pepper into the slow cooker. Pour in chicken broth and dot with unsalted butter.
02 - Cover and cook on low heat for 5 hours, or until chicken is tender.
03 - Remove chicken from slow cooker, shred using two forks, then return to the cooker.
04 - Whisk all-purpose flour with heavy cream until smooth. Stir this mixture into the slow cooker along with frozen peas.
05 - In a separate bowl, combine all-purpose flour, baking powder, and salt. Add melted butter and whole milk, stirring until just combined. Fold in fresh parsley if using.
06 - Drop tablespoon-sized portions of dumpling dough onto the surface of the stew, forming about 10 to 12 dumplings.
07 - Cover and cook on high heat for 1 hour, or until dumplings are fully puffed and cooked through.
08 - Taste and adjust seasoning if necessary. Serve warm.