1. Cut the tomatoes into chunks if they are large and put them in a blender or food processor with the cucumber, bread, oil, vinegar, garlic, and 1 cup water; sprinkle with salt and pepper and pulse the machine on and off until smooth.
  2. If the mixture seems too thick, thin it by gradually adding water, 1 tablespoon at a time.
  3. Taste, adjust the seasoning with salt, pepper, or vinegar, and serve right away or refrigerate and eat within a couple of hours.
  4. Garnish each serving with the bell pepper, scallions, and a drizzle of olive oil.