What is the theme in The Making of a Chef: Mastering Heat at the Culinary Institute of America by Michael Ruhlman?

One of the first things that Ruhlman learns while at the CIA is perseverance. Erica, one of the students in the Skills class with Ruhlman, becomes a symbol of the importance of perseverance while taking her courses there. Initially, she burns or destroys everything she tries to cook. Even Chef Pardus gives up hope for her.