Heh, mustard sandwiches. I thought I was the only one.
One of my favorites was school food, the sliced turkey roll and mashed potatoes with the wierd green gravy glaze that would be poured over everything.
Our "school food" peanut butter was mixed with honey and I loved it, but it took me forever to figure out why the Peter Pan stuff right out of the jar didn't taste as good as the peanut butter at school.