fruit is good for those, but im pretty sure you wouldnt want to put rotting animal product in there. 1. Pheonix worms consume vegetable matter, not animal product, correct? 2. Animal product is a breeding ground for harmful bacteria not only for chams, but humans as well. 3. I would not be keeping this in my house, so meat especially would attract scavengers such as raccoons.
If I had one, I would stick primarily to fruit/veg waste. Also, you would still need to make sure you are not putting things that are toxic to chams such as tomatoes and whatnot in there.