Here’s the part that shocks people: Fish sauce. Yes, the stuff that smells like a forgotten sock. It’s the soul of the broth. Without it, you just have beef water. With it, you have umami lightning in a bowl.
Don’t be scared. It doesn’t taste fishy. It adds salt and a funky, deep, savory kick that makes you crave more. It’s the secret handshake of Vietnamese cooking. Add a splash. Then add another one. You’ll know when it’s right because your tongue will do a happy dance.
