Chilled Zucchini and Basil Soup

In a small saucepan, heat oil over medium heat. Add onion; cook until tender, about 5 minutes. Add garlic; cook until fragrant, about 1 minute.

In the container of a blender, place onion mixture, zucchini, stock, basil, lemon zest and juice, salt, and pepper; process until smooth. Serve at room temperature or chilled. Garnish with oil and basil, if desired.