Soup-e Kadoo Sabz ba Piaz (سوپ کدو سبز با پیاز) — Persian Zucchini and Onion Soup

• 300 gWhite onion (finely diced (about 2 medium))
• 30 mlOlive oil (about 2 tablespoons)
• 7 gSea salt (about 1 1/4 teaspoons, plus more to taste)
• 1 gBlack pepper (about 1/2 teaspoon, plus more to taste)
• 4 gCurry powder (about 2 teaspoons; mild or hot to preference)
• 700 gZucchini (trimmed and cut into 2 cm chunks (about 4 medium))
• 70 gBroken rice (nim-daneh) (rinsed in cool water until mostly clear)
• 1000 mlChicken broth (low-sodium preferred)
• 180 gPlain yogurt (full-fat or 2%, at room temperature)

Instructions

1. 1

   Rinse the broken rice in a fine sieve under cool running water for 30–45 seconds, swishing with your fingers, until the water runs mostly clear. Drain well. Meanwhile, bring the yogurt to room temperature so it blends smoothly later and is less likely to curdle.

2. 2

   Heat the olive oil in a heavy pot over medium heat for 1 minute. Add the diced onion and 3 g (about 1/2 teaspoon) of the salt. Cook 10–12 minutes, stirring every 1–2 minutes, until the onion is very soft and translucent with light golden edges, but not browned.

3. 3

   Add the curry powder and black pepper to the onions and stir constantly for 45–60 seconds to bloom the spices. Add the zucchini and cook 5 minutes, stirring, until the pieces look glossy and begin to soften slightly; this step builds sweetness before adding the broth.

4. 4

   Pour in the chicken broth and add the rinsed broken rice plus the remaining 4 g (about 3/4 teaspoon) salt. Increase heat to high and bring to a gentle boil, about 6–8 minutes. Reduce to low, cover partially, and simmer 20–25 minutes, stirring every 5 minutes so rice does not stick.

5. 5

   When the rice is very tender and the zucchini is fully soft, turn off the heat. Blend the soup until silky using an immersion blender, 1–2 minutes, or carefully blend in batches in a countertop blender (vent the lid). Return to low heat and simmer 2 minutes to reheat and unify texture.

6. 6

   Temper the yogurt: whisk 180 g yogurt in a bowl until smooth. Ladle in 120 ml (1/2 cup) of hot soup gradually while whisking, then pour the warmed yogurt mixture back into the pot. Keep the heat low and warm 2–3 minutes without boiling. Taste and adjust salt and pepper before serving.