This term is believed by American's to be a common phrase in Australia. This was originally due to an
Australian tourism
advertisement starring Paul Hogan that was aired in America from 1984 - 1990.
Barbie is a slang term in Australia for barbeque, alternatively known
around the world as a barbecue or BBQ.
Although shrimp are known as prawns in Australia, the wording of the advertisement was designed to minimise confusion in American audiences.