What was the one thing Zoe told raj when she went to his shop feeling hungry - ratburger?

In the novel "Ratburger" by David Walliams, Zoe tells Raj that she is feeling hungry and would like a burger. Raj then offers her a burger, which she later discovers is made from rats. This revelation leads to a series of events in the story as Zoe tries to uncover the truth about the burgers being sold at Raj's shop.