Billy is really the one to ask about Gumbo
I sometimes cheat making Gumbo as a roux is (sort of) a living, breathing thing and can be tricky until you get used to making it
Is a decent shortcut
Also gumbo really needs Andouille sausage to get the taste right
http://www.gumbopages.com/food/andouille.html.
I prefer seafood gumbo over any other type but you can use just about any meat, use left overs if you like. Call your friends tell them it's a come as you are and bring something from their refrigerator for the gumbo party, beer accepted.
Once you get your roux going you can save some or give some to a friend so they can get started
Here's a couple more but I can't vouch for them
http://www.gumbopages.com/food/soups/index.html