Good question. I have never had chateaubriand but it sounds like it might be good. Quick web searches indicate that some of the major steak houses as well as others have it such as David Burke's, Chicago Cut, Tavern on Rush and Sabatinos. Maybe someone will chime in that has had it.
Toria
"I like this place and willingly could waste my time in it" - As You Like It,
W. Shakespeare