Step 1

For the soup: Place the chickpeas and pinto beans in separate medium bowls, cover with cold water by 2 inches and soak at room temperature for 8 hours.

Step 2

When the chickpeas and beans are ready, drain them and transfer to separate 2-quart saucepans, cover with cold water by 3 inches and bring to a boil over high heat. Reduce the heat to a simmer and cook until tender, 45 minutes to 1 hour, then drain. If the water comes below the beans before they’re completely cooked, add more water to cover.

Step 3

When the chickpeas and beans are almost ready, heat 2 tablespoons of the oil in a large pot over medium heat. Add the onions and cook, stirring occasionally, until they start to get golden and soften, about 10 minutes. Add the garlic and cook, stirring occasionally, for 1 minute. Add 1/2 teaspoon of the turmeric and 2 teaspoons salt and stir to combine.

Step 4

Add the cooked chickpeas and beans and 6 cups water and bring to a simmer. Stir in the lentils, spinach, parsley and cilantro, then simmer, covered, until the lentils are tender, 20 to 30 minutes.

Step 5

Meanwhile, add the remaining 3 tablespoons oil, the remaining 1/2 teaspoon turmeric and the dried mint to a small skillet. Turn the heat to medium and cook, stirring occasionally, until the mint starts shimmering and sizzling, about 5 minutes.

Step 6

When the lentils are ready, add the mint mixture and reshteh to the pot. Stir together and bring to a simmer, then cover and cook, stirring occasionally, until the noodles are soft, but not mushy, 15 to 20 minutes. The soup should be thick, similar to chili (see Cook’s Note). If it’s too thick, add 1/2 cup water and simmer 5 minutes more.

Step 7

If the finished soup looks watery, mix 1 tablespoon all-purpose flour with 1/3 cup water, then stir it in and simmer until the soup thickens, 5 to 10 minutes.

Step 8

For serving: Heat 1 tablespoon of the oil in a small skillet over medium heat. Add the onions and cook, stirring occasionally, until golden brown, about 10 minutes. Add 1/2 teaspoon of the turmeric and cook, stirring occasionally, 2 minutes more. Set the onions aside.

Step 9

Heat another 1 tablespoon of the oil in a small skillet over medium-low heat. Add the garlic and cook, stirring occasionally, until golden and crisp, about 2 minutes. Set the garlic aside.

Step 10

Combine the dried mint and remaining 2 tablespoons oil and 1/2 teaspoon turmeric in a small skillet. Turn the heat to medium and cook until the mint becomes shimmery, toasted and fragrant, about 5 minutes. Set the mint aside.

Step 11

Ladle the ash reshteh into a large tureen or individual bowls and top as you like with Kashk and the reserved onions, garlic and mint.

Step 12

Scoop the yogurt into a large pot and add 2 cups water. Whisk until the water is fully incorporated and there are no lumps. Place the pot over medium heat and stir constantly until the yogurt comes to a boil, 15 to 20 minutes.

Step 13

Reduce the heat to medium-low and simmer, stirring occasionally, until the yogurt is pretty thick and has lightly splattering bubbles, about 1 1/2 hours. The yogurt will separate and most of the water should be evaporated. Raise the heat to medium-high and stir constantly until the mixture is quite thick and lumpy and the color is light beige, 20 to 30 minutes. Remove from the heat and let cool for 20 minutes.

Step 14

Pour the kashk into a nut-milk bag and squeeze out and discard as much liquid as possible; you want to end up with dry pulp. Place the kashk in a blender, add 1/2 cup water and blend on high speed until creamy, about 1 minute. Add an additional 1 tablespoon water if needed to create a smooth consistency similar to mayonnaise. Add 3/4 teaspoon salt and blend to incorporate. The kashk should taste somewhat salty and sour. Add more salt, if needed.

Step 15

The kashk will keep, refrigerated in an airtight container, for up to 5 days. Stir before using.

Step 16

You can also freeze the kashk for up to 2 months. Thaw in the refrigerator, then stir before using.