Preheat the oven to 225 degrees Celsius (430 degrees Fahrenheit)
Cut the top 1/3 off of the garlic bulb so that the cloves are exposed and place it on a baking sheet along with the 5 red peppers. Drizzle the peppers and garlic with olive oil and bake in the oven for 25 minutes flipping the peppers half way through cooking to evenly brown.
Once the skins of the peppers have begun to blacken and blister, remove the tray from the oven and allow to cool before peeling of the skins.
Squeeze each clove of garlic out of the bulb and place in a blender or food processor along with the peppers, pine nuts and basil. Sprinkle with salt and then blend until smooth. The sauce can be kept in the fridge for up to a week.