In a large pot, boil chicken thighs in salted water for 1 hour.
Remove chicken, shred, and set aside. Reserve broth.
Add milk to the broth until it looks creamy. Bring to a soft boil.
Mix Bisquick dumpling dough according to biscuit recipe and double it. Add salt and pepper.
Drop dumplings by spoonfuls into the boiling broth.
Boil uncovered for 10 minutes.
Cover and simmer for another 10 minutes.
Stir in shredded chicken. Taste and season as needed.
Serve hot with extra black pepper.