Prescription spaghetti sauce.

My sister has this rare disorder where if she eats spaghetti with regular sauce she has a complete freak out spazz attack, kicking and screaming and all that.  Luckily, the doctors gave her a prescription for a special kind of spaghetti sauce, so when we have spaghetti she gets her own.  Supposedly it tastes just like the regular stuff, except without the going crazy part, but we're not allowed to eat it because it might cause a chemical reaction.