We have a good practice at Kensho: a new employee delivers a presentation about his or her career and
interests after spending 3-4 weeks working with us.
The format is very loose, usually it lasts 30 minutes over pizzas.
We specifically do not give any direction, except
"tell your coworkers something they still don't know about you". We buy plenty of food, and have light-hearted banter.
These presentation proved that even after interviewing and working with someone, there are things to be discovered. We found people with passion for poetry, making games, researching wind speeds, and other random things. Having a person work a month on the team before making the presentation made him or her comfortable sharing these things.
I usually ask the presenter how we could change Kensho for the better based on their previous experience. This usually is a jumping point for an honest and free-flowing discussion how we could improve things. Again, being at the company for some time before offering personal opinion makes people a lot more comfortable.