Step 1: In a large, powerful blender, combine the chopped tomatoes, cucumber, bell pepper, red onion, and garlic. If using, add the slice of stale white bread (crusts removed), soaked in water and squeezed dry.
Step 2: Pour in the extra virgin olive oil and red wine vinegar. Season with salt and black pepper.
Step 3: Blend the mixture on high speed until it is completely smooth. This may take a few minutes. If you desire a thinner consistency, you can add 1/4 to 1/2 cup of cold water or vegetable juice, a little at a time, until you reach your preferred texture.
Step 4: Taste the gazpacho and adjust the seasoning as needed. You might want a little more salt, pepper, or vinegar to brighten the flavors.
Step 5: Transfer the gazpacho to an airtight container. Chill in the refrigerator for at least 2 hours, or ideally, for 4-6 hours, or even overnight, to allow the flavors to meld and the soup to become thoroughly cold.
Step 6: Before serving, give the gazpacho a good stir. Pour into chilled bowls or glasses. Garnish generously with the reserved diced cucumber, bell pepper, and red onion. Drizzle with a little extra virgin olive oil. Serve immediately and enjoy this authentic gazpacho recipe.