Potato Leek Soup (Liquidised) | IDDSI Level 3 Recipe

IDDSI Level 3 (Liquidised) | 45 minutes | Easy | Vegetarian

Potato leek soup is a classic Western-style preparation that adapts extremely well to IDDSI Level 3. The starch from the potatoes creates a naturally thick, smooth base, while leeks provide mild onion-like sweetness and soluble dietary fibre. Using full-fat cream or soya cream produces a satisfying, energy-dense flowing liquid — particularly valuable for elderly residents with poor appetite who need maximum calories per millilitre consumed. This is one of the most filling Level 3 dishes in the vegetarian repertoire.

Ingredients (3–4 servings)

• 350 g floury potatoes (peeled and diced into 2 cm pieces)
• 2 medium leeks (approximately 250 g; white and pale green parts only; dark green tops removed; rinsed thoroughly between layers to remove grit)
• 1 tablespoon olive oil or unsalted butter
• 900 ml vegetable stock
• 80 ml full-fat cream or soya cream (for richness)
• 1/2 teaspoon salt
• 1/4 teaspoon white pepper
• Pinch of grated nutmeg (optional)

Method

1. Slice leeks into 1 cm rounds; rinse thoroughly under running water to remove all sand from between the layers
2. Heat olive oil or butter in a medium saucepan over low-medium heat; add leeks and sauté gently for 8–10 minutes until completely soft, translucent and sweet — do not brown or caramelise
3. Add diced potato and vegetable stock; bring to the boil; reduce heat to a steady simmer; cover and cook for 20–25 minutes until potatoes are completely tender (test with a knife — no resistance at all)
4. Remove from heat; allow to cool for 5 minutes; transfer all contents to a blender
5. Blend on high for 90 seconds until completely smooth
6. Pass through a fine-mesh sieve into a clean saucepan, pressing firmly; discard all fibre and solids
7. Return to low heat; stir in cream; season with salt, pepper and nutmeg; adjust consistency with hot water if needed to achieve Level 3 flowing consistency

Texture Test

IDDSI Level 3 (Liquidised) confirmation: Tilt a loaded spoon — the soup should flow slowly and continuously, leaving a thin coating on the back of the spoon. IDDSI syringe test: 1–10 ml should be expelled over 10 seconds at 45 degrees. The liquid must be completely particle-free and no leek fibre should be detectable.

Safety Notes

⚠️ Leek layer rinsing is critical — leeks trap significant quantities of grit between their layers; rinsing after slicing is more effective than washing whole leeks.

⚠️ Sieving is mandatory — leek fibre persists through even thorough blending; fine-mesh sieving is non-negotiable for Level 3 compliance.

⚠️ Dark green leek tops — the dark green portions are very fibrous and strongly flavoured; use only the white and pale green sections.

⚠️ Serving temperature — confirm the soup is below 60°C before serving.

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)

Potatoes: 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 190 kcal per serving (250 ml), 4 g protein, 28 g carbohydrate, 8 g fat. Leeks contain prebiotics (fructooligosaccharides) that support beneficial gut bacteria — important for elderly residents whose gut microbiome diversity is commonly reduced. Potatoes provide readily available energy as well as vitamin C and potassium.