Complex sentence: In addition to this the traditional fillings that include onions, lettuce, and tomato may be supplemented by extra fillings that may include bulgur (cooked wheat), hummus, cheese and tabouli.
Split into simpler sentences: In addition to this the traditional fillings that include onions, lettuce, and tomato extra filling may be used as supplements. These may include bulgur (cooked wheat), hummus, cheese and tabouli.