That's not up to the parents, I can't given them a box with some kind of rougail, or a galette-saucisse or even just green peas with carrots. They don't have a microwave.

It has to be cold and eaten with the hands, and "not too special", anything other than sliced bread with some kind of meat or spread inside is explicitly frowned upon.

I think it is region or school system specific? Here in Go! Flanders kids get served warm food by the school and they’re also welcome to bring their own lunch if they want to.

From what we found, no public school (Go! or gemeente) in Antwerp does that, brooddoos in all of them.

All schools in West Flanders do provide lunch though, and at least some in East Flanders too (obviously we only looked up the areas that matter to us and we didn't conduct an exhaustive study though). So we just concluded that it depends on the province.

At the very least it does not depend on the school system or the region since it varies within Flanders and within the Go! system.