Soak the torn bread chunks in cold water for 5 minutes until saturated. Squeeze out as much water as possible and set aside.
Core and roughly chop the tomatoes, peel and chop the cucumber, seed and chop the bell pepper, quarter the onion, and peel the garlic cloves.
Place half the tomatoes, cucumber, pepper, onion, both garlic cloves, squeezed bread, cumin, salt, pepper, olive oil, sherry vinegar, and ice-cold water into the blender. Blend on high for 60 seconds until completely smooth.
Add the remaining half of the tomatoes, cucumber, and green pepper to the blender with the smooth base. Blend again for 30-60 seconds on high.
For an ultra-silky texture, pour through a fine-mesh strainer set over a bowl, pressing with a ladle to extract all the liquid. Discard the solids.
Taste the gazpacho and adjust seasoning with additional salt, sherry vinegar, or water to achieve desired flavor and consistency.
Transfer to an airtight container and refrigerate for at least 2 hours, preferably 4 hours or overnight for best flavor development.
Stir or shake well before serving. Ladle into bowls or glasses, drizzle generously with olive oil, and garnish with diced cucumber, tomato, croutons, fresh herbs, and cracked black pepper.