Add all ingredients to a pot and bring to a boil. Reduce to a gentle simmer and simmer for about 40 minutes to an hour, until any remaining chicken on the carcass is softened and may be easily removed.
Remove chicken from carcass, shred, cover and refrigerate until the soup is ready to be made. Return the carcass to the pot to continue to simmer gently two to three hours until broth reaches desired flavor.
Strain broth and defat If desired, strain and place in the refrigerator until fat has risen to the surface and may be easily removed.
For the Soup itself:
Bring broth, oregano, carrots, celery, and onion to a boil and simmer for about 15 to 20 minutes, or until tender.
Add reserved chicken, cooked rice, parsley, salt, and pepper. Squeeze in a tablespoon of lemon or add two teaspoons of white vinegar or white wine vinegar. Taste and adjust seasonings.
Serve with lemon as a garnish.
Note: Hold back a little broth when first making the soup – then you can control how brothy you want it to be. Save any extra broth for when the soup is reheated; it may thicken up and can be thinned with broth or water,
Find it online: https://frugalhausfrau.com/2015/04/08/chicken-rice-soup/