Anthropology

It was a fermented fish sauce used in ancient civilizations.

"Garum is a rich source of umami flavoring, including monosodium glutamate. It was used along with murri in medieval Byzantine and Arab cuisine to give a savory flavor to dishes and used as a condiment in the cuisines of ancient Greece, Rome, Carthage and later Byzantium.

"When mixed with wine (oenogarum, a popular Byzantine sauce), vinegar, black pepper, or oil, garum enhances the flavor of a wide variety of dishes, including boiled veal and steamed mussels, even pear-and-honey soufflé. Diluted with water (hydrogarum) it was distributed to Roman legions. Pliny the Elder remarked in his Natural History that it could be diluted to the colour of honey wine and drunk.

https://en.m.wikipedia.org/wiki/Garum