Wow; garum. I always figured the closest analogue (in our culture) was Worchestershire; I think I read that in Reay Tannahill’s Food in History.

http://www.foodreference.com/html/garumr.html

http://www.romans-in-britain.org.uk/arl_roman_recipes-garum_fish_sauce.htm

http://www.pbs.org/wgbh/nova/lostempires/roman/garum.html

Tom