Hot and Sour Soup

Hot and sour soup is a tangy, peppery broth thickened just enough to carry tofu and silky ribbons of egg. It is Sichuan and Beijing's answer to a cold day, built to hit sour, hot and savoury all in the same spoonful.

What it really is

A light broth is soured sharply with vinegar and given its heat from white or black pepper rather than chilli, then thickened just slightly with a little starch so the tofu cubes and other solids stay suspended rather than sinking. Beaten egg is streamed in at the very end over the surface of the simmering broth, where it sets instantly into thin ribbons rather than clumping into curds.

The egg goes in last, off direct heat. Streamed into broth that's boiling too hard, it scrambles into small lumps instead of the fine ribbons the soup is known for; a gentler simmer is what keeps the strands thin and silky.

How it is served

• In a bowl, often with a few drops of chilli oil or sesame oil added at the table.
• As a starter before a larger meal, rarely as the main dish itself.
• With white pepper on the table for guests who want more heat.

How to write it on the menu

• Flag the egg and the soy.
• It's naturally vegetarian in its tofu-based form; note if pork or another meat is added, since many versions include it.
• Note that confidence on the nutrition figures is low, since the broth-to-solid ratio varies widely between kitchens.