Bring chicken stock to a boil. Add the chicken, salt, and pepper. Return to a boil.
Meanwhile, mix the baking mix with milk. Turn out on to a lightly floured surface and knead just until blended. Roll out flat (to about 1/4 inch) and using a pizza cutter, slice into 1 inch strips about 2 inches long.
Drop dumplings into boiling broth one at a time, stirring as needed. Cover, reduce heat slightly, and boil for 15 to 20 minutes.