The Imperial Chinese Restaurant in Olathe has what it terms a "Traditiona Chinese" Dim Sum buffet every Saturday and Sunday during lunch only.
About 20 dim sum items including several cold dishes. Very authentic stuff. I've never seen anything like it in the KC area. I've been three times and while I didn't like every item overall I highly recommend it. So far out of my three visits I've only seen one other none Chinese there.
11957 S. Strang Line Rd