Chilled leek and avocado soup | Reader's Digest Asia

Ingredients

• 1 tablespoon extra virgin olive oil
• 500 g leeks, white part only, halved lengthwise and thinly sliced
• 1 clove garlic, finely chopped
• 3 cups (750 ml) vegetable or chicken stock, preferably homemade
• 1 large ripe avocado
• ½ cup (125 g) low–fat natural yogurt
• 1 tablespoon lime juice
• 2 tablespoons chopped fresh coriander
• salt
• pepper
• 8–12 ice cubes (optional)
• slices of limes
• prigs of fresh coriander