Place turkey necks in a stockpot. Add water to cover. Over high heat, bring to a boil; reduce to a bubbling simmer and cook for 15 minutes. Rinse turkey in cold water; set aside. Wash out the pot to use for the soup.

Over medium heat, heat oil. Add fennel and celery; sauté for five to seven minutes. Add garlic; sauté until fragrant.

Peel and chop remaining veggies; add to the pot with the herbs. Add turkey necks. Season with salt and pepper, if using. Add water- it should just cover all the vegetables.

Bring soup to a boil. Reduce to a simmer; cook for four to six hours.

Once cool enough to handle, remove turkey necks from soup. Separate the meat from the bones. Return shredded meat to pot. Heat and serve.