Fish Sauce
About: Fish sauce is made from anchovies (or any small fish), water, and salt and left to ferment for up to a year. Fish sauce is one of the oldest ingredients in the world. I’ve read that soy sauce was invented as a way to create a cheaper alternative to fish sauce thousands of years ago in China. Fish sauce is essential to Thai food.
Brands: ‘Squid Brand’ (pictured) and ‘Oyster Brand’ are recommended. Tipparos brand is not recommended. Make sure you buy a Thai brand as other (mostly Vietnamese) brands taste very different. Fish sauce brands vary greatly in quality and fishiness.
Note: If you are vegetarian, you can usually get away with substituting fish sauce for either sea salt or white soy sauce, depending on the recipe.