Stuffed shells are usually served with a sauce such as marinara or Alfredo. They also pair well with vegetables like broccoli, spinach, and peppers.  A salad is also a great accompaniment to stuffed shells. Grated cheese like Parmesan or Asiago can also be sprinkled on top for added flavor and crunch.  Finally, a crusty loaf of bread makes the perfect side to sop up all the delicious sauce from your stuffed shell dish!