Step 1Put the olive oil, parsley, dill and cilantro in a bowl along with the pistachios, lemon juice and some salt and pepper, and blitz with a hand blender until the mixture is finely chopped and has the consistency of pesto. If you need to slacken the mixture, add a bit more oil.
Step 1Heat a large saucepan over medium heat and add enough olive oil to generously coat the base of the pan. Add the butternut squash, diced onions, garlic, leeks and potatoes, and cook, without browning, until the vegetables soften slightly, about 30 minutes, stirring occasionally.
Step 2Add the tomatoes, cumin, cinnamon, paprika and hot pepper paste, and give it all a good stir to ensure the spices evenly coat the vegetables. Cover the vegetables completely with water, add a generous amount of salt (I would suggest at least 4 teaspoons) and black pepper. Stir once more and continue to cook at a gentle boil until the squash is tender when poked with a knife, about 30 minutes.
Step 3Purée the mixture in a food processor or blender until you get a lovely, even, smooth soup. Once smooth, add the chickpeas and their liquid, and stir well.
Step 4Adjust the consistency of the soup with additional water if desired, then taste and adjust seasoning if needed. Cook an additional 20 minutes, stirring occasionally, then add the zucchini and cook for a final 20 minutes before serving.
Step 5While the soup is cooking, drizzle some olive oil into a large frying pan set over high heat, and fry the sliced onion until browned and crispy. Add the reserved chickpeas and brown them along with the onions. Using a slotted spoon, remove the onions and chickpeas from the pan and set aside. This makes about 3½ quarts soup.
Step 6Pour the soup into large bowls (preferably wide, shallow ones), then generously crumble the feta on top. Drizzle a couple of tablespoons of the herb oil into each bowl over the feta. Finally, add the reserved crispy fried onions and chickpeas.