Directions

• Fill an extra-large bowl with ice and water, and place a large bowl over top; set aside. Heat olive oil in a large pot over medium. Add onion, leek, shallots, and garlic; cook, stirring occasionally, until vegetables are softened, about 6 minutes.
• Add lemon thyme to pot; cook, stirring constantly, 1 minute. Add broth, and bring to a simmer over medium-high. Add zucchini and salt; increase heat to high, and bring to a gentle boil. Let boil until zucchini is tender, about 3 minutes.
• Add spinach, parsley, and basil to pot. As soon as greens are wilted, pour mixture into prepared bowl in ice bath. Stir mixture constantly to cool quickly and preserve color, about 5 minutes. Remove and discard lemon thyme. Working in 2 to 3 batches, transfer solids to a blender using a slotted spoon, and process until very smooth and creamy, adding enough liquid from bowl to blender to achieve a thin consistency, about 1 minute per batch.
• Pour soup through a fine wire-mesh strainer into an airtight container. Season with additional salt to taste. Cover soup and remaining greens cooking liquid in bowl, and refrigerate until chilled, about 1 hour, or until ready to serve.
• Just before serving, bring a medium pot of water to a boil over high. Meanwhile, prepare a bowl of ice-cold water; set aside. Add turnip and squash slices to boiling water; cook 1 minute. Transfer to prepared bowl of cold water using a slotted spoon; let cool slightly, about 30 seconds. Drain and pat slices dry; wipe bowl dry. Season turnips and squash to taste with lemon juice, salt, and pepper. Set aside.
• Taste and adjust soup seasoning as needed. If needed, stir in up to 1/2 cup reserved greens cooking liquid, 1/4 cup at a time, to thin soup until it is just thin enough to coat the back of a spoon. Serve soup garnished with turnip and squash slices and drizzled with extra-virgin olive oil.