Under the grill on a baking sheet, roast the tomato until charred and soft, turning once. Let cool.
If using whole chillies, de stem and de seed, split them so they lay flat and toast in a dry, medium- hot pan until fragrant but take care not to burn them or they will taste bitter. Place them into a bowl and cover with just boiled water, keep submerged with a small plate until they are soft, about 15 mins.
In the same pan that you toasted the chillies, turn down to medium and toast the garlic with the skin on, tuning as it browns and becomes sweet. Let cool and peel.
In a jug suitable for a stick blender, add all of the ingredients, blend until smooth, push the puree through a sieve into another bowl, check seasoning and serve.