When I think of an easy, crowd-pleasing thing to bring back from Vatican City, rice or grain pack from Vatican City is a good pick because it does not need much explanation when you hand it over. Grains, pasta and rice are not glamorous, but they are useful, cheap and often taste different from the UK supermarket version. I would rate it higher when it is locally made, clearly labelled and easy to use at home, and lower when it is just tourist packaging.