Halve and core the peppers and bake with the cut surface facing down in a very hot oven (220 degrees) or grill in an electric grill until the skin becomes blistered and almost black. Place in a plastic freezer bag while still hot, close tightly and allow to cool.
Put tomatoes in boiling water for 1 minute, rinse immediately in cold water, peel, core and cut into 2 cm pieces. Peel the cooled peppers and cut into 2 cm pieces. Carefully mix the bell pepper and tomato pieces. Finely chop 1 clove of garlic.
For the sauce, whip 1 tablespoon of vinegar or 2 tablespoons of lemon juice, 2 tablespoons of olive oil and 3 tablespoons of other vegetable oil using a mixer. Stir in pepper and salt as desired, 1/2 teaspoon sugar and the garlic, mix into the vegetables and let steep for at least 1 hour.
Variations:
Season with cumin or add some finely chopped parsley. If very good olive oil is available that does not taste sharp, then only this can be used.