I know it may seem intimidating, but I find that vegan fresh rolls (raw spring rolls) are awesome for pot lucks and they're not nearly as difficult to make as many people think. My wife is GF and my best friend is vegan so I make them for every event we have.
The ingredients are inexpensive, and you'll most likely use any left over ingredients in other dishes later. When made without meat they keep unrefridgerated for hours (although I would suggest keeping them covered until eating time so they don't dry out) and you can add shrimp or bbq pork to them if you or any of your guests are meat eaters (although totally not necessary, 'cause they're awesome on their own).