Cheese Substitute?

Cheese Substitute?

One item I struggle with, is cheese. I don't really miss it, but there are times that it is the ingredient that adds the moisture and even binds together the food - such as quesadillas. Without cheese, you just have dry chicken in your tortillas. What's a good option for this? Any time I'm looking for GF/DF I have to be mindful of the glycemic index as well, so appreciate an option that is GI friendly!
Elaine