Prepare the Ingredients: Start by peeling and pitting the avocados, chopping the cucumber after peeling and seeding it, and mincing the garlic cloves.
Blend the Soup: In a blender, combine the avocados, cucumber, Greek yogurt, cold vegetable broth, lime juice, mint leaves, and minced garlic. Blend on high until the mixture is smooth and creamy.
Season: Taste the soup and season with salt and freshly ground black pepper as needed. You can adjust the thickness by adding more vegetable broth if necessary.
Chill: Transfer the blended soup to a large bowl or container, cover with plastic wrap, and refrigerate for at least 1 hour to allow the flavors to meld together and the soup to chill thoroughly.
Serve: Once chilled, give the soup a good stir, and do a final taste test for seasoning. Pour the soup into individual bowls and garnish with additional fresh mint leaves. For a touch of richness, drizzle a small amount of olive oil over each serving if desired.
Enjoy: Serve the Chilled Avocado Soup immediately after garnishing for the best flavor and texture.