Lots of good suggestions (enchiladas, eclairs, etoufee[mmmmm…]), but I’ve gotta second (third?) the empanadas idea here. There was this bakery in Houston (La Piñata, for all you Houstonians out there) that served the most delicious pumpkin empanadas. The pineapple ones were out of this world as well. Pastry heaven! Mmmmmm…
Plus, if you want a non-dessert item, you can make meat or potato fillings too! sköt has given you a really good-sounding recipe; go for it!
Does this have to be something that is already made, or can there be some assembly by the teacher? If teacher is willing to put something together, how about egg creams?
Of course, that wouldn’t fly for any kid with dairy or chocolate issues, but there’s been no mention of allergies or dietary requirements that have to be considered. (And that’s odd, I was under the impression that schools were getting away from parent-supplied food so as to avoid that kind of problem.) Did the teacher mention that at all, LunaSea?
Otherwise, I’m all in favor of little tiny eclairs. (Kids do love “mini” food, too.) But then, I’m always in favor of any kind of eclairs.
(Oops, in thinking on it, eclairs wouldn’t be suitable for kids with chocolate or dairy issues either!)