beat him up and steal his leica. then you have 11 bladed aperture.

bokeh depends on many factors, not just aperture blades. it depends on how wide open you're shooting the lens at and correspondingly depth of field, and of course the optical quality of the glass. the more blades though, the rounder bokeh is in general. remember though that if you use your lense wide open, not stopped down any, then the aperture blades are withdrawn and so number is irrelevant.

and don't forget about what you're actually taking a picture of- the subject is important too!

what kind of camera are you using? i'm sure some people will swear that your uncle's bokeh is so good because he is using a leica, but you can get good bokeh with almost any camera. just open the aperture up all the way!