Let us start with Silphium, a spice so popular that its picture ended up on a coin, and so valuable that the Romans stored it in their public treasury. Silphium grew only in a very small tract of land in ancient Cyrenaica (modern-day Libya), appearing, according to Pliny the Elder, after a mysterious black rain fell upon the land. (Pliny the Elder, Natural History, 19.15) Just as quickly as it appeared, however, it vanished. The same passage of Pliny puts this down to over-grazing by the local sheep, and because it apparently could not be cultivated. Whatever the reason, Silphium soon became a relic of the past:
Within living memory, only one stalk has been found, being sent to the Emperor Nero as a 'curiosity'.- Pliny the Elder, Natural History, 19.15
Bad Nero, eating the last of our Silphium like that. However, whilst we might never experience the supposedly sensational taste of Silphium itself, we do have access to its inferior cousin, Asafoetida. As Silphium slipped from Rome's grasp, Asafoetida, a poor substitute for the real thing, soon came to be called by that name. Given that most the Apicius recipes were collected after Silphium had vanished, it is Asafoetida that they call for, and it is Asafoetida which we shall use.
Asafoetida doesn't exactly scream 'add me to your food', as it smells like an extremely pungent garlic/leek/onion crossover. The flavour, like the smell, is a combination of these three ingredients, and adds a savoury quality to food. Asafoetida is rarely used in isolation, and is instead added to help harmonise other ingredients in a dish, a task which it performs well.
If you're after Silphium, note that, according to Pliny, it makes sheep fall asleep and goats sneeze. If your goats aren't sneezing, and your sheep are still jumping fences, then you might just have to settle for Asafoetida. Luckily, Asafoetida is readily available; just check the spices at your local supermarket. It is also sold as 'Hing' in Indian and Asian food stores if you happen to have any nearby.
- Leek - whilst it shares qualities with garlic, onion, and leek, it is leek which has the savoury undertones most closely matching Asafoetida. Make sure to chop it up finely.
- Garlic Salt
- Onion Powder