Laser is a spice known to the Ancient Rome from near the Greek colony of Kyrene in modern-day Libya, used extensively as a flavor enhancer (the word "umami" comes to mind). It was said to be from the fennel family, somewhat like asafoetida in strength, but tastily pungent and milder -- it was also used for birth control, and as a tea. Pliny gives detailed instructions for identification and harvesting, but cautions the last known stalk of it was presented to the Emperor Nero. The bane of all who seek to emulate Apicius, efforts are now underway to identify and rebreed this valuable commodity.

In my own form of reconstructed Roman cookery, I use Worchestershire sauce, or pine nuts soaked in it.