The stupid meal accessories are the remnants of the summoning spell. That is specifically stated on the meal that has the maze on it.

http://www.giantitp.com/comics/erf0118.html

It was a well crafted spell. So much so that it does it's job properly even when the caster is unaware of the specific requirements of both the casting and the object of the caster. "Fully automated." No doubt the exact wording of the spell has a monstrous quantity of logical checks and rechecks, like a big computer program.