Orange chicken at Panda contains wheat, soy, egg, and dairy products. [0] These are all things that are commonly used in fast food to thicken up the taste. Wheat, soy and dairy also have a small element of physical addiction from opioids - it's not just that people like the taste of these things.

[0] https://s3.amazonaws.com/PandaExpressWebsite/files/pdf/Nutri...