Stock: Break up the carcass and removing skin, and place in a large stock pot. Add the 12 cups of water, all all the chopped vegetables and spices listed in the "stock" list. Bring to a boil, then let simmer for about 2 hours, until the turkey meat separates from the bones. Take the pot off the heat, and remove all the turkey parts, place on a cookie sheet to cool for easy handling. After the meat has cooled enough to handle, remove all the chunks of meat, and toss out all the remaining bones and skin.
Strain the broth into a large bowl, and throw away all the vegetables. Let the strained broth cool enough to skim the fat from the top - depending on how de-fatted you desire. Return the broth to the stock pot.
Soup: Now add all the fresh vegetables from the "soup" list. This list is totally negotiable. At this point you can omit any of the veggies you don't care for (don't be afraid of the turnips, they are quite tasty and add a lovely zing) or you can add any other veggies you choose. If you want to substitute potatoes for the rice - go for it.
Simmer for 1 hour until rice is done and veggies are tender.
Serve with hearty bread. This makes enough for a large family, with enough to freeze for later, or enjoy for lunch the next day.