In a blender or food processor, combine the diced cucumbers, tomatoes, red onion, bell pepper, and garlic. Blend until smooth.
Add the vegetable broth, olive oil, red wine vinegar, salt, black pepper, and cayenne pepper (if using). Blend again until well combined and smooth.
Taste and adjust seasoning if necessary. If the mixture is too thick, add a little more vegetable broth to reach your desired consistency.
Transfer the gazpacho to a large bowl or pitcher and cover. Refrigerate for at least 2 hours, or until well chilled.
Serve in bowls, garnished with fresh herbs. Enjoy!