Time: 20 min4 servingsapprox. 180 kcal / serving (estimated)approx. 7 g protein / serving
Lemon soup is a speciality of the old Hungarian bourgeois kitchen: made with egg yolks, sour cream and freshly squeezed lemon juice, it is tangy, silky and almost custard-like. It may seem surprising today, yet it is a very light, refreshing first course, especially before a heavier main. The secret is patient stirring, because the egg is sensitive to heat.
In a separate bowl, mix the egg yolks with the sour cream until smooth.
Add the strained lemon juice and keep stirring until smooth.
When the water boils, turn the heat to medium and pour in the egg and sour cream mixture in a thin stream, stirring constantly.
Keep stirring until it just comes to the boil - this takes a few minutes.
Take off the heat at once and keep stirring for another minute so the egg doesn't curdle.
Strain through a clean sieve and serve at once.
Based on: A jó házikonyha (a classic Hungarian cookbook), modernised. Calories and protein are estimated.
Tips
Pour the egg mixture into the water in a thin stream, stirring constantly, because a sudden blast of heat makes the yolks clump at once.
Take the pan off the heat as soon as the soup just comes to the boil and keep stirring for another minute, because the heat of the pan goes on cooking the egg.
Use only freshly squeezed lemon juice, because the preservatives in bottled juice and the missing aroma of the zest are immediately noticeable in the soup.
Frequently asked questions
What should I do if the egg curdles?
Strain the soup through a fine sieve straight away, or blitz it with a stick blender, and it will largely regain its silky texture. Next time, work over a lower heat.
What does this soup go with?
Its light, tangy flavour makes it a good opener for roast meats and richer main courses. A few croutons or small dumplings can be added if you want it more substantial.