Vegetarian ghormeh sabzi

Step 1: Heat 4 tablespoons of 3 ⅝ tbsp sunflower oil in a large heavy pot over a medium heat. Add 7 oz flat-leaf parsley, 3 ½ oz fresh coriander and 3 ½ oz chives and fry, stirring every minute or two, for 15–20 minutes. They will collapse, darken from bright to deep bottle green and smell toasty rather than fresh.

Step 2: Stir in 2 tbsp dried fenugreek leaves for the last minute. A common mistake is adding too much fenugreek or frying it from the start: it burns and turns the whole stew bitter.

Step 3: Tip the herbs into a bowl. Add the rest of 2 ⅜ tbsp sunflower oil to the pot and fry 2 onions over a medium heat for 8–10 minutes, until golden. Stir in 1 tsp ground turmeric for 30 seconds.

Step 4: Add 10 ½ oz chestnut mushrooms and fry over a medium-high heat for 6–8 minutes, until they have given off their water and started to brown.

Step 5: Return the herbs, add 1 lb cooked kidney beans, 4 dried limes, 3 ¾ cups water, 1 ½ tsp salt and ½ tsp black pepper. Bring to the boil, then cover and simmer over a low heat for 40 minutes, stirring now and then. Press the limes against the pot halfway through so they fill with sauce and sink.

Step 6: Taste. The stew should be thick, glossy with a little oil on the surface, and sour in a deep, rounded way. Add 2 tbsp lime juice if it needs more sharpness, and more salt if needed.

Step 7: Rest for 10 minutes off the heat; like most khoresh it tastes even better the next day. Serve over chelow, warning guests that the limes are for squeezing, not eating whole.