Blister the skins of the peppers over a flame or under the grill. Put in a covered bowl for 10 minutes then peel, deseed, cut into strips and put on a serving plate.
Blanch, refresh and peel the tomatoes. Purée in a blender or liquidizer and push through a sieve into a bowl.
Peel, smash and chop the garlic and add it to the bowl. Stir in the vinegar and oil