- Use a sharp knife and cutting board to dice the watermelon into roughly 1-inch cubes, then transfer them into a large mixing bowl. 
- Add the minced garlic and sherry vinegar to the watermelon cubes. Stir gently to distribute the flavors evenly. Let sit for about 5 minutes to allow the vinegar to marinate the fruit slightly. 
- Transfer the marinated watermelon mixture to a blender. Blend on high speed until completely smooth and no chunks remain, about 30 seconds. The mixture should be a vibrant, homogeneous pink liquid. 
- Pour the blended soup into a clean bowl or container, then season with salt and freshly ground pepper to taste. Stir well to incorporate the seasonings. 
- Cover the bowl with plastic wrap and chill the soup in the refrigerator for at least 1 hour. The cold enhances the refreshing quality and helps the flavors meld together. 
- Serve the chilled watermelon soup in bowls, optionally garnished with fresh herbs, small watermelon cubes, or a drizzle of extra vinegar for added brightness. The final dish should be cold, smooth, and vividly colored, with a refreshing aroma.