Can be prepared in 45 minutes or less but requires additional unattended time.
Ingredients
1 large leek (white and pale green parts only), chopped fine and washed well (about 1 1/2 cups)
3/4 cup finely chopped onion
1 tablespoon minced garlic
2 tablespoons olive oil
a 1/2-pound russet (baking) potato
1 1/2 pounds zucchini, sliced thin (about 4 cups)
3 cups low-salt chicken broth
1/3 cup heavy cream
1 tablespoon fresh lemon juice plus additional to taste
ice water for thinning soup
lemon slices for garnish
Directions
In a large heavy saucepan cook leek, onion, and garlic with salt and pepper to taste in oil over moderately low heat, stirring, until leek is softened. Peel potato and cut into 1-inch pieces. Add potato, zucchini, and broth to leek mixture. Simmer mixture, covered, 15 minutes, or until potato is very tender.
In a blender purée mixture in batches until very smooth, transferring as puréed to a bowl. Stir in cream, 1 tablespoon lemon juice, and salt and pepper to taste and chill soup at least 6 hours or overnight.
Thin soup with ice water and season with additional lemon juice and salt and pepper.
