Tip the bread into a bowl, season to taste with salt and pepper and add the olive oil and half of the red wine vinegar.
Remove the tomato skins by placing the tomatoes into boiling water for a few seconds and refreshing in a bowl of ice cold water. The skins should now peel away easily. Add the tomatoes to the bread, along with the cucumber and red onion. Scatter over the finely chopped garlic and add a pinch of salt. Mix until well combined.
Pour in the remaining red wine vinegar, plus more to taste, add the basil leaves and mix together with your hands until well combined. Serve.