BillD, I would have thought that caramel wouldn't work with salt until I tried it.

Maybe I should issue a challenge for everyone on this thread to try at least one PB & .. combination we would never think is appetising and report back here.

I'm planning to try the PB & mayo (and maybe also PB, mayo & horseradish) later today. I might even be brave enough to try PB & Vegemite, and PB & gherkin. I might do the whole smorgasbord, who knows?