Place chicken in a large soup kettle; add the broth, 1 teaspoon kosher salt and enough water to cover the chicken. Bring to a boil. Reduce heat; simmer for 55-65 minutes or until meat is tender, skimming the surface as foam rises., Remove chicken and set aside until cool enough to handle. Strain broth and skim fat. Return broth to the kettle; add the carrots, celery, onion, garlic, pepper and remaining salt. Bring to a boil. Reduce heat; simmer for 15 minutes or until carrots are tender., Meanwhile, in a small bowl, whisk eggs and oil. Add matzo ball mix and onion; toss with a fork until combined. Cover and refrigerate for 15 minutes., Remove and discard skin and bones from chicken; chop chicken and add to soup. Stir in parsley. Bring to a boil. Drop 12 rounded teaspoonfuls of matzo ball dough into boiling soup. Reduce heat; cover and simmer for 20-25 minutes or until a toothpick inserted into a matzo ball comes out clean (do not lift cover while simmering)., With a slotted spoon, carefully remove matzo balls and place one in each soup bowl. Ladle soup over top.