Add the chicken breasts, diced onion, sliced carrots, sliced celery, minced garlic, chicken broth, dried thyme, dried parsley, salt, black pepper, and paprika to the crockpot.
Cover and cook on low for 6–7 hours or on high for 3–4 hours.
Shred the chicken directly in the crockpot using two forks.
Stir in the frozen peas.
In a separate bowl, combine the flour, baking powder, salt, and chopped fresh parsley.
Pour in the whole milk and melted butter and stir just until combined.
Drop spoonfuls of the dumpling dough evenly over the hot chicken mixture.
Cover the crockpot and cook for 1 hour on high without lifting the lid.
Check that the dumplings are puffed and cooked through before serving.