When I have a BBQ, even where all the guests are meat eaters, I still like to have a potato salad and vegetable skewers and bread and sometimes a regular salad and roasted corn and sometimes roasted eggplant. I like to think if there was a vegetarian there, they'd be well catered for by default without me having to really do anything different. I love meat, and for a BBQ it's typically the star of the show, but you're going to want a supporting cast.