In a bowl combine the bread with water and let it stand for at least 20 minutes or until it's soft.
Drain the bread and squeeze out as much water as you can.Crumble the bread and place it in a serving bowl. Scatter the tomatoes, onions and chopped basil over the top.Dress Panzanella with extra-virgin olive oil and vinegar. Season with salt and pepper and toss well.Taste and adjust the seasoning with more oil, salt and vinegar.Leave Panzanella to stand for 15 minutes and serve at room temperature.