In a small saucepan, bring your bone broth to a light boil over medium-high heat. Flavor it with fish sauce and/or salt to taste.

Crack the egg in a small bowl and season with a few additional drops of fish sauce and a pinch of salt. Whisk well with a fork.

Remove the bone broth from the heat and stir the soup with a whisk as you slowly pour in the whisked egg.

The egg should cook on contact with the hot liquid even though you’ve removed the saucepan from the heat. Transfer the soup to a bowl. Garnish with your favorite toppings (sliced green onion, cilantro, and/or chili flakes).