Stephen Ryback is a level 35 cooking trainer located in Old Town in the human city of Stormwind.
The name is derived from the actor Steven Seagal and his character Casey Ryback in the 1992 film Under Siege where Seagal played a ex-Navy SEAL who was a cook aboard a US battleship. Nearby Ryback is Erika Tate a level 30 cooking vendor. This is a reference to the character Jordan Tate in the same movie played by the actress Erika Eleniak. Stormwind guards refer to the film by saying "From the way he handles a knife, I don't think he was always a chef."
See List of Stormwind NPCs.