Step 1

Place the turkey and onion in a 5-quart slow cooker. In a large bowl, whisk the soup, water, garlic, tarragon, salt and pepper until blended, then pour the mixture over the top of the turkey. Cook, covered, on low until the meat is tender, six to eight hours.

Step 2

Remove the turkey from the slow cooker. When it's cool enough to handle, remove the meat from the bones, discarding the bones. Shred the meat with two forks. Whisk the sour cream into the cooking juices, then return the meat to the slow cooker. Serve over noodles.