A Comm for Historymemes

Explanation: Romans were inordinately fond of a kind of fermented fish sauce they called garum. Like wine, it had low-quality varieties, which, also like low-quality wine, were considered the essential part of even a slave's rations; and high-quality varieties, which could cost a year's wages for a common laborer for a single container! The Romans put their fermented fish sauce in everything - on their bread, in their porridge, on their salads, even in their wine! De gustibus non disputandem est - there's no accounting for taste!

Tuna and large fish were traditionally used for "garum", while small fish were used for "liquamen". (Though the naming changed with time to reflect production processes rather than raw materials).

Garum was always expensive, while liquamen was initially cheaper and the byproducts of garum production (muria and allec) were the cheapest of them all, and probably the latter was what was given to slaves.

It is available in some specialized supermarkets, I think at least one Spanish version is available in the US. In fact, there are several versions available from the same country, but with modernized recipes.

If you can find a bottle, here's a recipe for you: https://www.historicalcookingclasses.com/garum/

In fact, some high-end places tend to fabricate their own garum with different bases than fish: https://www.foodandwine.com/condiments/why-chefs-have-loved-garum-since-ancient-times

What a weird blue tunic.