01 - Add chicken thighs, diced onion, sliced carrots, sliced celery, minced garlic, chicken broth, dried thyme, dried parsley, dried rosemary, bay leaf, black pepper, and salt to the slow cooker. Stir thoroughly to combine all ingredients.
02 - Cover the slow cooker and cook on low setting for 4 hours until chicken is extremely tender and easily shreds.
03 - Remove cooked chicken from the slow cooker using tongs. Shred completely using two forks, then return shredded chicken to the slow cooker. Remove and discard the bay leaf.
04 - Stir frozen peas and heavy cream into the slow cooker, mixing until evenly distributed throughout the stew.
05 - In a medium mixing bowl, whisk together all-purpose flour, baking powder, and salt. Cut cold butter into small cubes and incorporate into the flour mixture using your fingertips or a pastry cutter until the mixture resembles coarse breadcrumbs. Add whole milk and fresh parsley, stirring gently just until combined. Avoid overmixing.
06 - Using a tablespoon, drop rounded portions of dumpling dough onto the surface of the simmering stew. Position dumplings so they rest on top of the liquid rather than submerged.
07 - Cover the slow cooker and switch to high heat. Cook for 1 hour until dumplings are puffed, golden, and cooked through.
08 - Ladle the chicken and dumplings into serving bowls. Garnish with fresh parsley if desired and serve immediately while steaming.