Ingredients:

  • 2 tablespoons olive oil, plus more for garnish
  • 225g shallots (about 6), halved, thinly sliced
  • 1 teaspoon thyme leaves, fresh, finely chopped
  • 4 garlic cloves, thinly sliced
  • 900g zucchini (about 6), cut crosswise into 1/8-inch-thick rounds
  • 2 teaspoons salt
  • ¼ teaspoon black pepper, freshly ground
  • 4 cups vegetable or chicken broth, low-sodium
  • 2 cups California walnut halves, toasted, plus more for garnish
  • 3 cups (about 50g) basil leaves, fresh, packed, plus more for garnish
  • 1 cup yogurt, plain, low-fat
  • 1 teaspoon lemon juice, freshly squeezed

Preparation:

  1. Heat oil in a large saucepan over medium-high heat. When it shimmers, add shallots and cook, stirring occasionally, until golden brown, about 5 minutes. Add thyme and garlic and cook until fragrant.
  2. Stir in zucchini, salt, and pepper, reduce heat to medium, and cook, stirring occasionally, until zucchini is very soft, about 10 minutes. Add broth and simmer until zucchini is falling apart, for about 20 minutes.
  3. Place half of the zucchini mixture and half of the walnuts in a food processor fitted with a blade and process until smooth, for at least 2 minutes (use caution when blending hot liquids). Transfer to a medium bowl, then repeat with remaining soup.
  4. Place the soup bowl into a large bowl of ice water, and set aside to cool, stirring occasionally until it comes to room temperature, for about 20 to 30 minutes.
  5. Transfer this to the refrigerator to chill thoroughly, at least 1 hour. Meanwhile, blend or puree the basil, yogurt, and lemon juice together until smooth.
  6. Just before serving, stir in yogurt mixture, taste and adjust seasoning as desired. Serve topped with chopped walnuts, a drizzle of olive oil, and a few torn basil leaves.