Cut, core, and chop the vegetables. Place them in a large blender, along with olive oil and water, and blend until smooth. Season with salt, pepper, and more vinegar if needed. Cover and refrigerate until chilled all the way through.
In a large skillet over medium heat, add 2 tablespoons of olive oil. Stir in the cubed bread and sauté, stirring occasionally, until bread is golden and crisp. Remove from heat, season with salt, and let cool.
When ready to serve, divide soup among bowls. Top with homemade croutons, fresh parsley, and freshly ground pepper.