In a medium saucepan, combine the water, beans & lentils over medium heat. Bring to a boil, then reduce the heat to a light simmer. Cook, partially covered, until nearly tender.
Meanwhile, heat a small saucepan over medium heat. Add the rapeseed oil and swirl to coat the bottom of the pan. Stir in the dried mint and remove from the heat. Set aside.
In a medium skillet, . Add onions, and cook until softened and golden, 10 to 12 minutes. Stir in the turmeric to coat. Using a slotted spoon, transfer the onions to a small bowl and set aside.
4. Once the beans have simmered, add the spinach, parsley and scallions, and return to a light simmer. Cook partially covered, until the greens have dulled in color, 15 minutes. Stir in 1 tablespoon of the mint oil and season with salt and pepper.
In a small bowl, place the pinch of saffron, cover this with 2 tbsp boiling water & place a plate on top to cover.
Meanwhile, bring a large pot of salted water to a boil. Add the linguine and cook until al dente, 12 minutes. Drain the pasta and add to the soup. Adjust the seasoning as needed, then divide between bowls. Garnish with the fried onions, yogurt, mint oil and saffron water, then serve.