Cauliflower is a really awesome vegetable that can be used to replace carbier fare in recipes. If you can't or don't eat bread, but still want a flavorful, homey side for your turkey, consider making this cauliflower "stuffing" from delish. (Technically I think this would be a "dressing," but I'll let it slide.)
The original recipe (linked below) is absolutely packed with vegetables. In addition to cauliflower, you'll find onion, celery, carrots and mushrooms, but feel free to add whatever vegetables and herbs you use in your favourite stuffing. Just saute the onions, celery, and carrots until soft, and then add in chopped cauliflower and mushrooms.
Cook those down until tender, then add your favourite herbs. (Delish recommends a blend of parsley, rosemary, and sage.) Pour in some tasty broth, cover, and let cook until the cauliflower has absorbed the liquid (about fifteen minutes).