Spaghetti with a little butter melted on it.
You know the saddest part? My family wasn't 'poor.' My father just wouldn't give my mother money for groceries, and shopping for food was a woman's job. I don't know how we, or she, made it through until the divorce.
It's not always about the cost saving. Sometimes it's just because it gets more customers! Brominated flour, as an example.