I put a call out to folks about Australian food - either what "typical Aussie food" we would serve to international visitors; or what international guests would expect to eat as "typical Aussie food".
I did get a pavlova as a suggestion and lots of food including bush tucker flavors and ingredients but I ask myself if that is something that we would "typically" eat. For most folks, I think the answer would be 'no' - fabulous food, great ideas, but not "typical".
So, putting my thinking cap on, I think it would be a barbecue. It could be flash or regular; it could be steak or seafood but I think it would be a barbecue. Salads would include a coleslaw, a potato salad, a green salad and then a "chef's special" (ie whatever they wanted to throw together on the day). Dessert would include the pav, and probably a cheesecake and a fruit salad. It would be byo drinks but softies would be provided. The rest of it (including the budget) is entirely optional.
Any thoughts from others?