If I had to name just one ingredient that was key to the ancient world’s cuisine, it might be fish sauce.
All you need are fish and a lot of salt. An ingenious method of food preservation, its invention too deep in the past to ever know, alongside other legendary foods of yore like bread, beer, and cheese.
From Sumer onwards, almost all civilizations seem to have made the stuff. But it was the Romans who called it “garum” and recorded it into history. Fish sauce could be made at home by poor fishermen families, but there was also a highly expensive market for the very finest vintages of garum. Whatever quality, you can’t make Roman cuisine without it.