Kadu Sabz (کدو سبز) — Persian Creamy Zucchini and Leek Velouté

• 300 gLeeks (white and light green parts only), cleaned and sliced (Slice into 5 mm rounds; rinse well to remove grit)
• 600 gZucchini, diced (About 3 medium; cut into 2 cm cubes)
• 150 gCarrot, diced (About 1 large; cut into 1 cm cubes for even cooking)
• 30 gUnsalted butter (For sautéing and a velvety base)
• 15 mlOlive oil (Helps prevent butter from browning too quickly)
• 20 gAll-purpose flour (About 2 1/2 tbsp; thickens like a classic velouté)
• 900 mlChicken stock, low sodium (Warm if possible for smoother thickening)
• 120 mlHeavy cream (Add at the end; do not boil hard after adding)
• 0.5 tspGround nutmeg (Freshly grated if available)
• 1.25 tspFine sea salt (Adjust to taste depending on stock salinity)
• 0.5 tspBlack pepper, freshly ground (Add in stages and adjust at the end)

Instructions

1. 1

   Prepare the vegetables: trim leeks to the white and light green parts, slice, then soak in a bowl of cold water for 3 minutes and lift out to remove grit. Dice zucchini and carrot as noted. Warm the chicken stock in a small pot over low heat so it is hot but not boiling.

2. 2

   In a heavy pot, melt butter with olive oil over medium heat (about 160–175°C surface heat) for 1 minute. Add leeks and cook 8–10 minutes, stirring often, until very soft and sweet-smelling without browning. Add carrot and cook 3 minutes to begin softening.

3. 3

   Sprinkle flour evenly over the vegetables and stir continuously for 2 minutes to cook out raw flour taste. The mixture should look lightly pasty but not dry. Slowly pour in about 250 ml hot stock while whisking or stirring vigorously to prevent lumps, then add the remaining stock.

4. 4

   Add diced zucchini, salt, and black pepper. Bring to a gentle simmer over medium heat, then reduce to low and cover partially. Simmer 15–18 minutes, stirring every 5 minutes, until carrots are tender and zucchini is fully soft. Keep the simmer gentle to preserve a clean, fresh flavor.

5. 5

   Blend until completely smooth using an immersion blender, or carefully transfer to a blender in batches (do not fill more than halfway; vent the lid). Return to the pot and simmer uncovered for 3–5 minutes to reach a velvety, spoon-coating consistency.

6. 6

   Lower heat to the gentlest simmer. Stir in heavy cream and nutmeg and heat 2–3 minutes until steaming, avoiding a hard boil. Taste and adjust salt and pepper. Serve hot, or cool slightly and serve warm; the soup will thicken as it stands, so loosen with a splash of stock if needed.