"Great! You'd be the perfect candidate for this job!" (sarcastic tone; can be used to hand a responsibility from your side to them when you complain about something)
"If you're so good at it, why don't you go do it??" (say it in a cheerful way to avoid conflict)
"Good for you." (nodd your head and just say yeah, yeah. this shuts them up faster.)
These are the nice Fe ways of saying..."Put up or shutup, because right now your all talk and useless."