In a stockpot, saute onions in butter until tender. Stir in flour until blended. Gradually add water. Stir in the vegetables, one can of chicken, bouillon and 1/4 teaspoon pepper; bring to a boil., In a large bowl, combine the biscuit baking mix, parsley and remaining pepper. Stir in milk just until moistened. Fold in remaining chicken. , Drop by rounded tablespoonfuls onto simmering soup. Cover and simmer for 15 minutes or until a toothpick inserted in a dumpling comes out clean (do not lift cover while simmering).