Cut the crust off the bread. Pour water into a bowl and soak the crustless bread for about 10 minutes. Score the tomatoes crosswise and place in hot water for about 3 minutes. Then remove and peel the skin. Wash the cucumber and dice roughly.
Coarsely chop all tomatoes (stalk removed) except one. Halve, deseed, thoroughly wash the red and green bell peppers and also chop coarsely. Set aside 1 table spoon for garnish. Fine chop the peeled garlic, peel and coarsely dice the onion and squeeze out the soaked bread well.
Put everything into a kitchen mixer or a tall bowl. Puree everything until a viscous soup is formed. Then turn the speed down to low and gradually add the olive oil. It should be slowly incorporated.
Season your gazpacho with a bit of red wine vinegar (sherry vinegar or white wine vinegar will also work), add a pinch of sugar, season with salt and pepper.
Let it chill in the fridge for a few hours before eating. Ideally, it can even be left overnight.
Serve with toasted bread cubes and small pieces of Prosciutto.