The Roman meal unfolds in three stages. At dawn, the ientaculum, frugal: bread, cheese, olives. At midday, the prandium, quick and cold, eaten standing or on horseback. In the evening, the cena, which among the powerful proceeds in three acts: the gustatio (piquant appetizers and eggs), the mensa prima (meats and vegetables with garum), the mensa secunda (fruits, honey, sweet wine). But in the field, Aetius compresses all this: the Roman soldier eats a wheat porridge, bacon, and drinks his posca, without ceremony.

A fermented fish sauce with salt, a liquid ferment that flavors almost all Roman savory dishes. An ancient cousin of nuoc-mâm, it provides the deep umami that Romans cherished. At the table or in camp, a splash of garum transformed simple food into a Roman dish. It, more than any spice, marked a cuisine as "Roman."