You can have ravioli stuffed with different foods. Essentially, ravioli is a set of little pockets or envelopes so anything that can be poked inside and cooked fairly quickly, such as one or two of these: spinach, cheese, cooked rice, bulgar wheat, couscous, raisins, herbs and tomato, will make a tasty dish.
Obviously pieces of meat would not work for they would be too heavy for the delicate pasta that ravioli is made from, and take to long to cook.
