Its a bit like a BBQ/stir fry - but the contents are selected by you.
Last time I went all the basic ingredients are prepared in separate bays, (pre cut and ready to cook) and you pick out the bits you want (i.e. beef, chicken, carrots, cabbage, etc, etc) you then add the sauces you want (can be hot and spicy through to mild and sweet)
Take it over to the cooks who cook it on a great big shield/hot plate and your done. For cops like me a benefit is that you can go back again and again and again and try all kinds of combinations.