Scoop out the inside of half a melon, removing the seeds, using a melon baller. Be careful not to break the rind, as you'll use it as a serving bowl. Place the melon balls in a large bowl big enough to hold all the gazpacho ingredients and blend them together.

Add the peeled and chopped hard-boiled egg. Add the chopped onion to the egg and melon. Peel and chop the cucumber, then add it to the rest of the ingredients. Peel the garlic cloves and add them as well. Season with salt, olive oil, and vinegar to taste.

Blend everything together and adjust the salt, oil, and vinegar as needed. Pour the melon soup into the emptied melon rind and serve very cold. You can add ice cubes to the gazpacho just before serving to make sure it's extra chilled.