PreparationFor cilantro cream: Whisk sour cream, cilantro, and garlic in small bowl to blend. Season with salt and pepper. DO AHEAD: Can be made 1 day ahead. Cover and chill. For shrimp: Combine all ingredients in medium bowl. Cover and chill at least 4 hours or overnight. DO AHEAD: Can be made 1 day ahead. Keep chilled. For soup: Heat oil in heavy large pot over medium heat. Add onion; sauté until tender, about 8 minutes. Add garlic; stir 1 minute. Add zucchini; stir to coat. Stir in broth; bring to boil. Cover, reduce heat to mediumlow, and simmer until zucchini is tender, about 10 minutes. Cool to lukewarm. Add chopped cilantro. Working in batches, puree soup in blender until smooth. Transfer soup to large bowl. Season to taste with salt and pepper. Cover and chill until cold, about 4 hours. DO AHEAD: Can be made 1 day ahead. Keep chilled. Divide soup among bowls. Top each with shrimp, dividing equally. Spoon dollop of cilantro cream over each, garnish with cilantro sprigs, and serve.
PreparationFor cilantro cream: Whisk sour cream, cilantro, and garlic in small bowl to blend. Season with salt and pepper. DO AHEAD: Can be made 1 day ahead. Cover and chill. For shrimp: Combine all ingredients in medium bowl. Cover and chill at least 4 hours or overnight. DO AHEAD: Can be made 1 day ahead. Keep chilled. For soup: Heat oil in heavy large pot over medium heat. Add onion; sauté until tender, about 8 minutes. Add garlic; stir 1 minute. Add zucchini; stir to coat. Stir in broth; bring to boil. Cover, reduce heat to mediumlow, and simmer until zucchini is tender, about 10 minutes. Cool to lukewarm. Add chopped cilantro. Working in batches, puree soup in blender until smooth. Transfer soup to large bowl. Season to taste with salt and pepper. Cover and chill until cold, about 4 hours. DO AHEAD: Can be made 1 day ahead. Keep chilled. Divide soup among bowls. Top each with shrimp, dividing equally. Spoon dollop of cilantro cream over each, garnish with cilantro sprigs, and serve.