Complex sentence: In some places, quesadillas are also topped with other ingredients, in addition to the fillings they already have: avocado or guacamole, chopped onion, tomato, serrano chiles and cilantro are the most common.
Split into simpler sentences: In some places, quesadillas are also topped with other ingredients, in addition to the fillings they already have. Avocado or guacamole, chopped onion, tomato, serrano chiles and cilantro are the most common.