Heat balsamic vinegar in a pan. Put dry slices of bread on a deep baking tray and moisture carefully with warm vinegar. Do not allow to become too moist, the bread should not dissolve.
Combine tomatoes, olives and capers in a bowl and mix with the remaining vinegar. Dice the marinated bread coarsely and toss gently together with the basil.
If dry bread is not available, fresh bread can be toasted in the oven until dry.