We had learned some basic food vocabulary and the partitive article.
The brief was that they could put in anything they wanted - the more disgusting, the better. (It's a group of mostly boys!)
They didn't know the words for almost all of these things so I gave them dictionaries.
I've never seen children so excited about looking up words before.
Sadly (or not!) some of the words they were looking for were not in the school's dictionaries so we settled for some less horrific words.
So, by the end, we had some quite horrible stuff on them (I hope you're not eating)
We had:
Dans mon sandwich il y a du vomi.
Dans mon sandwich il y a de la morve.
Dans mon sandwich il y a des mouches.
Dans mon sandwich il y a des crottes.
You can see a pattern forming here, can't you?
Anyway the point was not to learn new words but to learn how to use a dictionary properly.
And have fun.
Which we did.