It's the mayo.
Ketchup or special sauce are standard. Mustard is Texas style.
This is kind of outdated, but in the 80s mayo on a burger was weird.
A lot of places California burger means avocado, too.
@Kurtroedeger @tyghebright you're blowing my mind.
I think there was also a time where "California " would signify bean sprouts
@rpardee @Kurtroedeger @tyghebright or perhaps avocado (at least in southern USA).
@rpardee @Kurtroedeger @tyghebright alfalfa spouts and avocado would make it totally Californian. What they’re selling is just a burger.
Oh yeah. The "California" sandwich of the 80s was (alfalfa) sprouts, turkey, and avo.
@rpardee @Kurtroedeger @tyghebright True. Very True.