Step 1: In a large pot or Dutch oven, combine chicken broth, celery ribs, and onion chunks. Add the halved chicken breasts, black pepper, and poultry seasoning. Bring to a gentle simmer over medium heat. Cook for 20-25 minutes, or until chicken is cooked through.
Step 2: Carefully remove the cooked chicken from the pot and set aside to cool slightly. Leave the celery and onion in the broth for now. Once cooled, shred the chicken using two forks or chop into bite-sized pieces. Discard the celery and onion from the broth before proceeding.
Step 3: While the chicken cools, prepare the dumpling dough. In a large bowl, whisk together the all-purpose flour, baking powder, and 1¼ tsp salt. Make a well in the center and pour in the milk. Mix with a spoon or your hands until a soft, shaggy dough forms. Do not overmix.
Step 4: Turn the dough out onto a lightly floured surface. Knead gently for about 1-2 minutes until it comes together. Using a rolling pin, roll the dough out to approximately 1/8 to 1/4 inch thick. Cut the dough into strips or squares, about 1x2 inches in size.
Step 5: Bring the chicken broth back to a gentle simmer. Add the 2 Tbsp of butter. Carefully drop the dumpling pieces into the simmering broth, one by one, ensuring they don't stick together. Do not overcrowd the pot; cook in batches if necessary.
Step 6: Cook the dumplings for 10-15 minutes, or until they are tender and cooked through. They should float to the top and be slightly chewy. Stir in the shredded chicken and heat through for a few minutes.
Step 7: Taste and adjust seasoning if needed. Ladle generous portions into bowls and garnish with fresh chopped parsley, if desired. Serve hot and enjoy your homemade Copycat Cracker Barrel Chicken and Dumplings!