Blanch the tomatoes in boiling water, once peeled, deseeded and drained from the cooking water dice the pulp. Place them in a sieve and drain for 15 minutes to allow them to loose all of their liquid.In the meanwhile cook the pasta, drain it al dente and cool it under running water, drain again and place it in a bowl, then sprinkle it with 2 tbsp of olive oil. Stone and chop the black olives, then chop the chive. Place the vinegar in a bowl, season with salt and pepper and stir until the salt has dissolved. Fold the oil in the sauce.Place the tomatoes in a bowl with the olives, the chive then dress these ingredients with the sauce and mix well with a wooden spoon. Then pour this cold sauce over the pasta and serve.