Preheat the oven to 200ºC. Slice the capsicum in half lengthways. Remove the core, seeds and white membrane from the capsicum. Place on an oven tray lined with baking paper, skin side up. Brush with a little olive oil. Roast for approximately 30 minutes or until the skins blister and blacken. Remove from oven and place on a plate. Cover with cling film. This will allow the capsicum to sweat and skins loosen. Once cool, remove the skins.