Some dishes can recover from less-than-ideal ingredients, but because gazpacho uses raw ingredients, it can’t hide sub-par produce. So be sure to use the best produce you can find, especially epic tomatoes.
In a large bowl, combine the tomatoes, bell pepper, onion, cucumber, vinegar, garlic, olive oil, and bread. In batches, process in a blender on high speed until very smooth, 3 to 4 minutes per batch.
Strain through a coarse strainer into a clean bowl. Season with salt, pepper, and the additional vinegar, if desired. Cover and chill for 1 hour.
To make the croutons: In a medium skillet, heat the oil and butter over medium heat. Add the garlic and cook, stirring, until golden brown. Remove the garlic and discard. Add the torn bread pieces and cook. tossing often, until golden brown.
Ladle the chilled soup into serving bowls. Garnish with the cucumber and parsley. Drizzle with olive oil and top with croutons