Turkey Matzo Ball Soup
Soup is always an obvious choice for leftover turkey. And while I'm pleased with my matzo ball skills, I'm not sure how truly authentic these are, although mine are quite light and tender.
My turkey was already very well seasoned, so I didn't need to add much to the stockpot. You can adjust your broth according, and can certainly add things like bay leaf, thyme springs, parsley stems, etc.