I would put Rice or grain pack from Democratic Republic of the Congo on the list for Democratic Republic of the Congo because it is the kind of thing that feels useful once you are home, not just another airport purchase. Grains, pasta and rice are not glamorous, but they are useful, cheap and often taste different from the UK supermarket version. The reason it works is that it gives you a quick reminder of the trip without needing to keep a fragile ornament safe forever.