Tomato Egg Drop Soup | IDDSI Level 3 Recipe

IDDSI Level 3 (Liquidised) | 25 minutes | Easy

Tomato egg drop soup is one of the most common everyday soups in Hong Kong cha chaan tengs and home kitchens — its gentle sweet-sour flavour is widely recognised as appetite-stimulating, making it particularly valuable for elderly residents with reduced appetite. For IDDSI Level 3, two adaptations are essential: (1) the tomato base must be fully blended until smooth, then strained through a fine-mesh sieve to remove all skin and seed fragments; (2) the beaten egg must be poured into the boiling soup in a thin stream while stirring continuously to produce fine, evenly dispersed ribbons (3mm or smaller) throughout the smooth soup base.

Ingredients (2–3 servings)

Soup base:

• 3 tomatoes (about 350g, core removed, cut into chunks)
• 800ml light chicken stock
• ¼ onion, finely diced (optional)
• 2 slices fresh ginger

Egg drop:

• 2 eggs (beaten with a pinch of salt and 1 teaspoon water)

Seasoning:

• ½ teaspoon salt
• ½ teaspoon sugar (to balance acidity)
• ½ teaspoon sesame oil
• Optional: 1 teaspoon cornflour + 2 teaspoons cold water (helps produce finer egg ribbons)

Method

1. Heat a small amount of oil in a pot over medium heat. Sauté the ginger slices and diced onion for 2 minutes until softened. Add the tomato chunks and stir-fry over high heat until the tomatoes break down and release their juices, about 5 minutes.
2. Add the chicken stock, bring to a boil, then reduce to a low simmer for 10 minutes until tomatoes are completely dissolved.
3. Remove the ginger slices. Use a hand blender to blend the soup completely smooth (about 1 minute). Strain through a fine-mesh sieve, pressing gently to extract maximum liquid while discarding skin and seed residue.
4. Return the strained soup to the pot and bring back to a boil. Season with salt and sugar. If using cornflour slurry, stir it in now and cook for 1 minute until slightly thickened.
5. Stir the soup in a circular motion to create a gentle vortex. Pour the beaten egg into the vortex in a slow, thin stream while continuing to stir gently for 5 seconds — this distributes the egg into fine ribbons throughout the soup.
6. Turn off the heat. Add sesame oil. Confirm that egg ribbons are fine (3–4mm) and evenly distributed with no large pieces.

Texture Test

Flow test: Passes Level 3 — the strained soup flows continuously from a tilted spoon and settles flat within 5 seconds. Egg ribbons are fine and evenly dispersed with no discrete solid pieces.

Solid particle check: After straining, no tomato skin, seeds or other particulates remain. Egg ribbons 3–4mm, fully incorporated into the flowing base.

Safety Notes

⚠️ Straining is not optional — tomato skin and seeds can pose a choking risk even when softened. Use a fine-mesh sieve (1–2mm aperture) and confirm that the strained soup flows smoothly with no visible particles.

⚠️ Egg ribbon size control — eggs poured in too quickly or with insufficient stirring can produce large pieces (>5mm). If this occurs, pass the finished soup through a fine sieve or blend briefly to break up any large pieces before serving.

⚠️ Serving temperature — tomato soup retains heat well. Check that temperature does not exceed 70°C before serving, particularly for residents with reduced oral sensation.

Sourcing Outside Hong Kong

For international care kitchens and home cooks outside Hong Kong, Cantonese ingredients are widely available at East and Southeast Asian grocery stores:

• United Kingdom: Wing Yip (Birmingham, London, Manchester), See Woo (London), Loon Fung (London)
• United States: 99 Ranch Market (West Coast), H Mart (East Coast), local Chinatown grocers
• Canada: T&T Supermarket (national chain), local Asian markets
• Australia: Burlington Supermarket, Tang’s, local Chinese grocers in Chinatown precincts
• Singapore & Malaysia: Sheng Siong, NTUC FairPrice (Singapore); Tesco, Mydin (Malaysia)
• Online: Sous Chef (UK/EU), Amazon.com (US), Yami.com (US)

Fresh tomatoes: universally available at any supermarket.

If a specific ingredient is unavailable in your region, the recipe notes alternative substitutions in the Ingredients section. For dishes requiring fresh Cantonese-specific ingredients (e.g. preserved century egg, fresh rice noodle rolls), check with your local East Asian grocer before substituting — texture compliance for IDDSI levels may require specific products.

Nutrition

Approximately 90 kcal per serving (about 250ml), 7g protein, 5g fat. Tomatoes are rich in lycopene (bioavailability increases significantly with cooking and the addition of fat) and vitamin C; eggs provide complete protein and B vitamins. The natural acidity of tomato stimulates saliva production, which can benefit residents with dry mouth (xerostomia) — a common side effect of many medications.

Cultural Note

Tomato egg drop soup occupies a unique place in Hong Kong food culture — found everywhere from primary school canteens to home dinner tables, it is one of the first dishes many Hong Kong children remember being cooked by their parents or grandparents. Presenting this familiar, comforting soup in a safe Level 3 format reconnects elderly residents with a specific and meaningful sensory memory, making mealtimes more emotionally engaging for those who have long been limited to unrecognisable blended food.