Finely chop ¼ of a cucumber and reserve for garnish. Peel the remaining cucumber and cut into chunks; place in a large bowl. Add in the tomatoes (and juices), ¼ cup red onion, ½ cup of cilantro leaves, red wine vinegar, and olive oil, stirring to combine. Season generously with salt and pepper.
Place half of the mixture in a blender or Vitamix and blend until as smooth as possible. Strain the mixture through a fine-mesh strainer, and repeat with the remaining tomato mixture.
Taste and adjust seasoning as necessary (I usually find it needs more salt and a splash more vinegar).
Place the mixture in the refrigerator and let chill, covered, for at least 2 hours.
Serve in bowls, garnished with the remaining cucumber, red onion, cilantro, mango, red and yellow cherry tomatoes, and a drizzle of olive oil.