show (someone) (one's) stuff
To demonstrate or display one's ability (to do something) in front of or for the benefit of someone. I've been training really hard all year, so I can't wait to go to tryouts and show the coaches my stuff. We're very excited to see what you have in store for us, Jen. Whenever you're ready, go ahead and show us your stuff!
show someone one's stuff
Fig. to show someone how well one can do something. We'll audition Kate now. Okay, Kate, show us your stuff.