In a large nonstick skillet coated with nonstick cooking spray, brown chicken. Add the broth, water, vegetables and seasonings. Bring to a boil. Reduce heat; simmer, uncovered, for 30 minutes.
Meanwhile, for dumplings, beat the egg whites and cottage cheese in a mixing bowl. Add water and salt. Stir in the flour; mix well.
Bring soup to a boil. Drop dumplings by tablespoonfuls onto the boiling soup. Reduce heat; cover and simmer for 15 minutes or until a toothpick inserted in dumplings comes out clean (do not lift cover while simmering) Serve immediately.