Start by cutting the stale bread into slices. Then reduce it into cubes using your hands or a knife. Put the bread in a bowl and wet it with about 2/3 cup (160 ml) of water and 3 tbsp of vinegar.* Mix well with a spoon or with your hands to make the bread absorb the water, and let it rest for about 30 minutes.
In the meantime, prepare the vegetables: wash the tomatoes and cut them into cubes. Peel the cucumber and cut it into pieces.
Cut the onion into very thin slices. Take the bread back and, if it is very wet, squeeze it a little with your hands. Transfer it to a large salad bowl
Add the tomatoes, cucumbers, onion, two pinches of salt, and a grind of pepper. Complete with 4 abundant spoons of extra virgin olive oil. Mix carefully, then add the basil leaves, broken up with your hands.
Stir again with a spoon, so that the ingredients blend perfectly. Cover the salad bowl and let the Tuscan panzanella rest in the refrigerator for at least 4 hours before serving, so that the bread is properly flavored.