The One with Ross's Sandwich

Plot:

Ross brings his leftover thanksgiving sandwich to work, but someone eats it. He finds out that it was his boss, who puts him on sabbatical and sends him to a psychiatrist for anger management therapy. Phoebe takes a literature class and asks Rachel to come with her, but instead of reading the books, Rachel comes and asks Phoebe what they're about right before the class begins. Monica takes the class instead of Rachel, but she tries to make the class more challenging and no one likes her.