The garum was the sauce made of fish with which the Romans insaporivano countless dishes (you see: https://www.pilloledistoria.it/1787/storia-antica/garum-liquamen-salsa-preferita-dai-romani).
Nell’city it was possible to find garum of varying quality, also very expensive, as the ways to achieve it, and the results from the flavor point of view and the gastronomic yield, were several.
The famous poet Marcus Valerius Martial (38 O 41-104 d.C.) describes the following method:
“Use oily fish such as sardines and mackerel, which must be added, in a portion of a third, entrails of various fish.
You have to have a well-pitched bath, the ability to thirty liters.
On the bottom of the tank, make another layer of dried herbs and tangy like dill, coriander, fennel, celery, mint, pepe, saffron and oregano.
On the bottom you have the guts and small whole fish, while larger ones should be cut into small pieces.
Above spread a layer the thickness of two fingers salt.
Repeat layers until the rim of the container.
Let stand for seven days.
Stir often for a few days.
At the end you will get a fairly thick liquid, which it is precisely the garum.
It will be preserved for a long time”.
A dressing more or less similar to garum It was already present in the Phoenician and Greek cuisine, but the first to make extensive use was the Romans (Photo gives: antinousgaygod.blogspot.com).