Mince a bit of the tomato, pepper, and cucumber for garnish, and set aside. Soak bread in a cup of the water for 5 minutes, then squeeze out excess water. Place bread in a blender or food processor with the remaining tomato, pepper, cucumber and water, garlic and vinegar; process until smooth, then add olive oil slowly with machine running. Season to taste with salt and pepper and refrigerate until ready to serve. Before serving, check seasoning again, and garnish with reserved tomato, pepper, cucumber, and garlic croutons.