Serious answer. I would order in some food and just allow some time for eating, chatting, etc. Then just explain you
want to everyone to get to know each other a little bit better and feel it's integral for what you are trying to accomplish. Have each person just go around the table and introduce themselves, where they're from, and share one unique thing about themselves. Allow for that part to go by fairly quick if it does.
I've always seen that seem to go over pretty well and help build comradery.