01 - Place the tomatoes, cucumber, red bell pepper, onion, garlic, and parsley or cilantro into a blender or food processor. Blend until mostly smooth, leaving some texture if desired.
02 - Add the olive oil, vinegar, cold water, salt, and pepper to the blender. Blend again until all ingredients are thoroughly combined and the mixture is uniform.
03 - Taste the gazpacho and adjust seasoning as needed. Add an extra splash of vinegar for brightness or a little more water to thin the consistency to your preference.
04 - For a smoother, more refined texture, pass the soup through a fine-mesh sieve, pressing with a spatula to extract as much liquid as possible. This step is optional.
05 - Transfer the gazpacho to a covered container and refrigerate for at least 2 hours, or until completely chilled and the flavors have melded together.
06 - Stir the gazpacho well before serving. Ladle into chilled bowls and top with your choice of diced cucumber, diced red bell pepper, chopped herbs, croutons, or a drizzle of olive oil.