Preheat the oven to Gas Mark 4, 180ºC, fan 160ºC. Place the peppers onto a roasting tray and fill with the tomatoes, anchovies, olives, garlic, chilli and half of the basil. Pour over the oil and vinegar and season.
Roast for 30 minutes or so until softened but still holding their shape. Serve scattered with the rest of the basil, a simple salad and crusty bread to mop up the juices.