Remove the crust from the bread slices and soak the slices in the wine vinegar for 20 minutes.

Meanwhile, chop the parsley and basil leaves very fine and place in a crockery bowl.

Squeeze the liquid out of the bread and put it in the bowl with the herbs, then add the tomato paste and start stirring with a wooden spoon. Add, little by little and stirring constantly, enough olive oil to make a smooth cream.

Taste for salt and pepper. Let the sauce rest, covered, in the refrigerator for 1 hour before serving.