In "Vendetta", episode 23 of Batman the Animated Series, Alfred says to Batman: "I've made your favorite, French onion soup".
While this may just be a throw-away line, helping to lead into the "crock/croc" revelation Alfred and Batman share (it's the first Killer Croc episode), this scene made me wonder: Is Batman's affinity/fondness/love for French onion soup mentioned elsewhere in canon?
I will accept answers showing evidence that Alfred, or any member of the Wayne family, has made a mean bowl of French onion soup in the past, and could have swayed Bruce from an early age.