Slice or tear the bread into large cubes (about 1-inch). Place them on a baking sheet and leave them out to harden overnight (if the bread is not old).
You could bake the bread in a 300 F oven until the crust is a little hardened but the inside is still soft. Made sure to move the bread around during the baking a couple of times.
Place the bread chunks into a small bowl. Add some lukewarm water on top of the bread chunks to let it soak in and soften the bread a little while you prep the vegetables and dressing. (It could take about ½ cup water).
Chop the tomatoes and cucumber into bite-sized pieces.Thinly slice the red onions.
In a small bowl, combine the olive oil, red wine vinegar, salt, and a few grinds of fresh pepper; whisk together.
In a large bowl combine bread and chopped vegetables. Pour on the vinaigrette and gently stir together to combine all the flavors.
Let the salad sit at least half an hour before serving, or up to 4 hours, and that's when all the magic happens!
Stir in fresh basil just before serving. Best eaten the day it’s made.