If you go to Wikipedia, they tell you this about fish sauce:
Fish sauce is a condiment that is derived from fish that have been allowed to ferment. It is an essential ingredient in many curries and sauces. Fish sauce is a staple ingredient in Vietnamese, Thai, Lao, Cambodian, and Filipino cuisine and is used in other Southeast Asian countries.But if you scroll down, you will find the story of European style fish sauce.
A similar fish sauce was ubiquitous in Classical Roman cooking, where in Latin it is known as garum or liquamen.... It was made of a variety of fish including tuna, mackerel, moray eel, and anchovies. This attitude derives in part from ancient authors who satirized the condiment, but mostly from the fact that fish sauce was generally unknown in the Western world until very recently. The truth is quite different, and in fact garum only smelled when it was being made. Once the process was complete it had a pleasant aroma for as long as it was usable.I bet you did not know that Worcestershire sauce was a variation of fish sauce!
In English it was formerly translated as fishpickle. The original Worcestershire sauce is a related product because it is fermented and contains anchovies.
The ancient authors were not kidding when they said fish sauce smells bad when you make it. The area between my part of Chanthaburi and Bangkok has many businesses that make fish sauce. If you have air conditioning in your car, you roll your windows up when you drive by a fish sauce processor. Once the fish sauce is ready to eat, it loses that smell.
It's too bad Europeans gave up on such a healthy condiment just because it smells bad when you make it. That's better, I think, than if it smelled bad when you eat it. At True Thai, we like Squid brand fish sauce.
But there is another point to this story. I am reminding you of how much Asians love fish sauce because I want True Thai's vegetarian customers to remember to tell us that they are vegetarians. If you do, we'll be sure to help you with your order. Many appetizers come with fish sauce or a fish sauce based dipping sauce, but we can substitute that if you like.