The best thing you never heard of is called “colatura di alici” or “garum” its ancient name. Garum and other similar fish-based sauces were the ketchup of the ancient world, mass produced in factories by the Romans, and sprinkled on anything savory. They usually made several versions: a dark-colored table condiment that was high in protein, a cooking sauce (sometimes called liquamen by historians, though often grouped together with garum), and a milder version called muria, explains food historian Sally Grainger. The fall of the Roman empire meant the end of its mass production, but the art of the fish sauce was not lost in Italy. The modern-day version, colatura di alici, is a saltier mixture of all three sauces. The video below shows you how is made.