I think the event was a learning experience for both host and guest. Obviously the host is trying to improve his skills, since he asked what was required.
The vegetables could've gone onto a glass or plastic dinner plate, or they could've been put on a paper plate, on top of a piece of plastic if needed. They could've been served in a take-out container. I would've brought a cheap disposable serving dish with the vegetables, but if I forgot, there are many ways to improvise.