Winter staple in our house: sweet potato soup. Super easy too.
Onions, celery, and carrots thrown in a dutch oven with some olive oil, cooked until they start to sweat (or longer, whatever). Add in your sweet potatoes and cook them for a few minutes too. Add some cinnamon, nutmeg, and a chipoltle pepper or two. Cover with chicken broth.
Simmer until everything is cooked through, then hit it with an immersion blender. Velvety smooth, super tasty, stupid simple to put together, surprisingly filling, and pretty good for you.