Name: Tomato and egg drop soup
Prep time: 5 min
Cook time: 20 min
Total time: 25 min
Cuisine: Chinese
Ingredients: 450 g ripe tomatoes (about 3 medium); 2 tbsp neutral oil; 2 spring onions, whites and greens sliced separately; 1 tsp sugar; 1 tsp fine salt, plus more to taste; 1 l water (or vegetable stock labelled gluten-free); ¼ tsp ground white pepper; 1½ tbsp cornstarch; 3 tbsp cold water; 3 eggs; 1 tsp toasted sesame oil

Tomato and egg drop soup

Ripe tomatoes cooked down in oil until jammy, simmered into a sweet-sour broth and finished with silky egg ribbons and sesame oil. China's everyday soup, in 25 minutes.

By the Soupmap Culinary Team

Prep: 5 min
Cook: 20 min
Total: 25 min
Effort: Easy
Serves: 4

Broth richness 3/10

Spice 1/10

Comfort 7/10

Ratings by the Soupmap Culinary Team, not readers.

Method

Cook the tomatoes

Cut out the tomato cores and cut the tomatoes into 2 cm chunks (to peel them first, see Tips). Beat the eggs with a pinch of salt in a jug until smooth, and stir the cornstarch into the 3 tbsp cold water in a cup.
Heat the oil in a saucepan over medium-high heat until it shimmers. Add the spring onion whites and stir for 30 seconds, until fragrant. Add the tomatoes, sugar and 1/2 tsp of the salt and stir-fry for 1 minute.
Turn the heat to medium and cook, pressing the tomatoes with the back of the spatula, until they've collapsed into a thick, jammy sauce and the oil around the edge has turned orange, 5–7 minutes.

Make the soup

Pour in the 1 l water, scrape up anything stuck to the pan and bring to a boil over high heat. Lower the heat to a lively simmer and cook for 5 minutes, so the tomato flavours the broth. Add the remaining 1/2 tsp salt and the white pepper, then taste: it should be bright, gently sweet-sour and well salted. Add more salt if it needs it, especially if you used water.
Stir the cornstarch mixture again, since it settles fast, and pour it into the simmering soup in a thin stream, stirring. Simmer for 1 minute, stirring, until the soup turns glossy and lightly coats a spoon.
Turn the heat down so the soup barely simmers. Give it one slow stir in a circle, then pour the egg in a thin stream over the moving surface, ideally through the tines of a fork. Leave it alone until the egg sets into soft, opaque ribbons, 20–30 seconds, then stir gently once and check that no runny egg is left.
Turn off the heat, stir in the sesame oil, scatter over the spring onion greens and serve.

Swaps

Cooking for coeliac disease or an allergy? Check every label: the notes below say which ones matter.

Gluten-free

Gluten-free as written with water. If you use stock instead, choose one labelled gluten-free, since many stocks and stock cubes contain wheat or barley.
Check that the cornstarch is labelled gluten-free. In some countries "cornflour" can be made from wheat (sold as wheaten cornflour), so read the packet rather than going by the name.

Plant-based

Without the egg it's no longer egg-flower soup, but a tomato and tofu soup in the same spirit is still lovely. Use water or vegetable stock labelled vegan, and after thickening in step 5, slide in 300 g silken tofu, cut into small cubes or broken into soft pieces with a spoon, and simmer gently for 2 minutes.

High-protein

As written a bowl has about 6 g protein, mostly from the egg. Use 5 eggs instead of 3, poured in the same way: about 3 g more per bowl.
Add 300 g firm tofu, in 2 cm cubes, with the water in step 4: about 9 g more per bowl.
Simmer 200 g peeled raw prawns in the soup until pink and opaque, about 2 minutes, before you thicken it: about 10 g more per bowl. It's then no longer vegetarian.

Tips

Let the tomatoes break down. Ripe, deep red tomatoes give the soup its colour and sweetness. Out of season, add 1 tbsp tomato paste with the tomatoes in step 2 for colour and depth; it's still vegetarian and, if it's just tomatoes, gluten-free.

Peeling is optional. Tomato skins curl into chewy strips in the soup. To peel, cut a shallow cross in the base of each tomato, cover them with boiling water for 1 minute, then drain and slip the skins off. It adds about 3 minutes.

Thicken first, then add the egg at a bare simmer. The lightly thickened broth holds the egg up in fine, floating ribbons, and gentle heat keeps them silky. Poured into a hard boil, the egg breaks into small curds.

White pepper, not black. White pepper's earthy heat is the classic seasoning for Chinese soups. Black pepper works but tastes sharper and shows as dark specks.

If you use stock, check the label. Many bought vegetable stocks and stock cubes contain wheat or barley, so choose one labelled gluten-free if that matters. Plain water is gluten-free and, with good tomatoes, all the soup needs.

Make ahead and storage

Cook the tomato base (steps 2–3) up to 2 days ahead and keep it covered in the fridge. With the base ready, the soup takes 10 minutes.

Leftovers keep for 2 days in the fridge. Reheat gently: the soup thins as it stands, so stir in 1 tsp cornstarch mixed with 1 tbsp water if needed. The egg will be a little firmer. Don't freeze it.

Variations

Silken tofu: add 200 g silken tofu, cut into 2 cm cubes, with the water in step 4. It's still vegetarian and gluten-free.

Ginger: fry 3 thin slices of fresh ginger with the spring onion whites for a warmer, sharper soup.

Coriander: finish with chopped coriander leaves instead of, or as well as, the spring onion greens.

With chicken stock: common in restaurants and richer. It's no longer vegetarian, and check the label if you need it gluten-free.

Tomato and egg drop soup

Ingredients

Soup

To finish