What is your "go to" recipe for impromptu meet your neightbor gatherings?

[Velos]

We enjoy the spur of the moment gatherings to meet neighbors or join in a parks social hour but am always stumped with what to bring other than pre-packaged snacks. 

What do you keep on hand for these gatherings?

And what is your "go to" recipe for spontaneous socials and gatherings?

[sandsys]

Freeze-dried foods where you just add water and wait a few minutes before serving. We once brought Backpacker's Pantry freeze-dried blueberry cheesecake to an impromptu gathering which was very different from what people normally bring. My favorite freeze-dried meal is Mountain House Beef Stroganoff with Noodles but you rarely see me sharing that one.

Linda Sand