I heard this exchange on The Big Bang Theory (a US sitcom).
Rajesh: You know who's got to be the bravest person in the Marvel Universe? Whoever has to give She-Hulk a bikini wax.
Howard: You want to talk brave, how about Captain America's undocumented Mexican gardener?
I am pretty sure that it doesn't mean "You want to talk in a brave manner". I think it means "Do you want to talk about brave"? But what does brave mean here? Does it mean a brave man or bravery or brave people? I am not sure.
I also would like to know whether it is possible to use other adjectives with to talk in the same way:
- I would like to talk happy ( = about happy people?)
- I would like to talk rich ( = about rich people?)