Preheat the oven to 180°C, gas mark 4. Whisk 3 tbsp of the oil with the garlic, add the bread and toss to coat. Tip onto a baking tray and bake for about 10 minutes until golden.
Meanwhile, whisk 3 tbsp extra virgin olive oil with the vinegar, season to taste and set aside.
Preheat a barbecue or griddle pan to a high heat, add the peppers and cook until blackened and charred all over. Put the peppers into a bowl, cover with clingfilm and leave to steam for 10 minutes. When cool enough to handle, rub the skins away, deseed and tear into long strips. Tip into the bowl with the dressing.
Meanwhile lightly char the tomatoes on the barbecue then roughly chop and add to the peppers. Toss to combine and leave to cool before tossing through the bread, capers and basil. Leave to sit for 20 minutes before serving.