Cut chickens into several pieces. Place chicken, onions, carrots, celery stalks, parsley, thyme, dill, garlic, salt, and pepper in a large stockpot. Add seven quarts of water. Bring to a boil and simmer for six hours. Turn burner off and let it sit for one hour. Strain. Pull the chicken off of the bone and reserve for another use.
Place chicken stock in refrigerator overnight. The next day, skim off the surface fat. Use immediately or freeze for up to 3 months.
In a large crock, heat olive oil until simmering. Add onions and sauté until translucent. Add garlic and sauté for 30 more seconds.
Add celery, carrots, 1/2 cup parsley, rosemary, Chinese five spice, salt and pepper, chicken, and stock. Stir ingredients well.
Bring mixture to a boil then reduce heat and let simmer for one hour, stirring occasionally. Ladle into bowls and serve with remaining parsley.