Avocado and Cucumber Soup

From: Chef Oliver Ridgeway, Grange Restaurant & Bar, Sacramento, CA. Yield: 4 servings.
    
12 oz. English cucumber, peeled, cut into 4 pieces
2 large fresh avocados, peeled, seeded, quartered (8 oz. each)
1 oz. green onion, cut into large pieces
2 cloves garlic, peeled
2 Tbsp. cilantro leaves, plus extra for garnish
4 Tbsp. fresh lemon juice
1 cup plain yogurt, plus extra for garnish
1 cup cold water or cold vegetable stock
1 cup ice cubes

Puree all ingredients until smooth. Season with salt and pepper. Garnish each serving with a swirl of yogurt and cilantro. Serve.