Combine bread and 1/2 cup water in a medium bowl.

Let stand until most of the water is absorbed, about 10 minutes.

Combine 1/4 cup chopped tomatoes, 1/4 cup chopped cucumber, and chopped parsley in a small bowl; stir to blend.

Set aside for garnish.

Combine bread mixture, remaining tomatoes, remaining cucumber, red bell pepper, extra-virgin olive oil, dry Sherry, red wine vinegar, and garlic cloves in a large bowl; stir to blend.

Working in 2 batches, add the bread-vegetable mixture to a blender and puree until smooth.

Strain the gazpacho into a large bowl.

Cover and refrigerate until very cold, about 2 hours.

Ladle the gazpacho into bowls.

Garnish with the reserved tomato-cucumber mixture.

Serve well chilled.