When we started cruising I made the classic mistake of anxiously provisioning for our first trip as if we would not see another shop for the next six months. It didn’t take long for us to realise that where there are people there is generally food for sale. However, some food are more ubiquitous than others.
Soy sauce, and Worcester sauce (aka Worcestershire sauce and salsa Inglesa) seemed to be available in even the most remote islands. On the other hand peanut butter, cheese and English mustard are tradeable in many places and, if the are to your taste, stock up on the Marmite and Vegemite.