In a food processor or blender puree tomatoes, onions, garlic, cucumber, red pepper, bread, olive oil and vinegar until very smooth, 2 minutes or more. Refrigerate several hours.
Before serving, season with salt and pepper and strain through a sieve if desired. Thin with ice water if needed. Divide among 6 soup bowls and offer choice of garnishes.
Recipe Courtesy of David Rosengarten