Fish sauce (made from the liquid of, yes, salted fermented fish) is a staple, used for seasoning instead of salt. It gives wonderful depth of flavor—what the Japanese call umami. But unless you’re cooking Southeast Asian food every week, a big bottle (it’s cheapest in big bottles) can sit in your cupboard unloved and unused for months—which is why we’ve rounded up our favorite ways to use it. It’s actually a lighter and more subtle seasoning than soy sauce.