
Fish sauce
Used in 2 recipes on RecipeWiki.
Fish sauce is a clear amber liquid made by fermenting fish, usually anchovies, with salt. It is the main salty seasoning in much of Southeast Asian cooking. From the bottle it smells strong and pungent, but cooked into a dish it turns into a deep, rounded savouriness with no fishy taste. It seasons the broth of Pho Bo and balances palm sugar and lime in Green Curry with Chicken and Thai Basil. Add it gradually and taste as you go, since it is far saltier than soy sauce. An opened bottle keeps for months, and darkening with age is normal.
Recipes with fish sauce

Green Curry with Chicken and Thai Basil
Cracking the coconut cream before the paste goes in is the step most recipes skip, and the one that decides whether this tastes fried or boiled.

Pho Bo
Charring the onion and ginger before they go near water is what makes the broth smell like pho rather than beef soup. Everything else is patience.