Place chicken and water in a Dutch oven. Cover and bring to a boil.
Reduce heat to simmer; cook until chicken is tender, about 30 minutes.
Remove chicken from kettle; bone and cube.
Return chicken to kettle along with the onion, celery, carrots, celery seed, 1 teaspoon of sage, salt and pepper.
Bring to a boil.
Cover and simmer for 45-60 minutes or until the vegetables are tender.
For dumplings, combine the biscuit mix, milk, parsley and remaining sage to form a stiff batter or use a can of biscuits.
Drop by tablespoonfuls into the simmering chicken mixture.
Cover and simmer for 15 minutes.