Preheat the oven to 180°C. Place a sheet of foil on a baking tray.
1. Peri-peri sauce Arrange the pepper, garlic bulb and onion on the foil, sprinkle the oil over then fold the foil over the vegetables. Bake for 20 minutes then remove from the oven and leave to cool.
2. Press out the garlic flesh from the cloves (it will be soft) and place along with the onion and chillies in the bowl of a food processor. Remove the skin of the pepper and add to the food processor. Pulse until fine.