- 1 tablespoon extra virgin olive oil
- 3 cups thinly sliced leeks
- 1 garlic clove, finely chopped
- 3 cups vegetable or chicken stock
- 1 large ripe avocado
- 1/2 cup plain low-fat yogurt
- 1 tablespoon fresh lime juice
- 2 tablespoons chopped fresh cilantro
- Salt and fresh-ground pepper
- To Garnish:
- 8 ice cubes (optional)
- Lime slices
- Fresh cilantro sprigs
- Heat the oil in a saucepan. Add the leeks and garlic and cook, stirring frequently, until the leeks are soft but not browned, about 10 minutes. Pour in the stock and bring to a boil. Cover the pan, reduce the heat, and simmer until the leeks are tender, about 10 minutes.
- Remove the soup from the heat and leave to cool slightly, then puree it in a blender or food processor. (Alternatively, the soup can be pureed in the saucepan with a handheld blender.) Pour the soup into a bowl and leave it to cool. Cover and chill well.
- Just before serving the soup, prepare the avocado. Halve the avocado and discard the seed. Scoop the flesh from the peel and press through a fine stainless-steel or nylon sieve. The avocado can also be pureed in a blender or food processor until smooth, adding a little of the chilled soup to thin the puree and make sure it is smooth.
- Stir the avocado puree into the soup together with the yogurt, lime juice, and cilantro. Add seasoning to taste, then ladle the soup into 4 bowls. Float 2 or 3 ice cubes in each bowl (optional). Add slices of lime and cilantro sprigs. Serve at once.