Tomato and egg noodle soup (Xihongshi jidan mian)

1. Score a cross in the base of the tomatoes, put them in boiling water for 30 seconds, peel and cut into wedges; slice the white and green parts of the spring onions separately; beat the eggs with a pinch of salt.

2. Heat 2 tablespoons of oil in the wok, pour in the eggs and cook them loosely into large curds, then remove.

3. In the remaining oil, fry the spring onion whites for 30 seconds, add the tomatoes and sugar and cook for 4-5 minutes, pressing with a spoon, until the tomatoes collapse into a sauce.

4. Pour in the water, add the soy sauce and the rest of the salt, bring to the boil, return the eggs and simmer for 2 minutes.

5. Meanwhile cook the noodles separately in water, drain and divide between bowls.

6. Pour over the tomato and egg soup, drizzle with sesame oil, sprinkle with the spring onion greens and serve.

Tip: This is one of the best-known dishes of Chinese home cooking: every student cooks it first. It's best in summer with ripe, fleshy tomatoes; in winter, boost the flavour with 1 tablespoon of tomato purée.