Begin by cleaning the squid: carefully separate the heads with their tentacles, then remove the guts, setting aside the ink sacks (be careful not to break them). Wash the squid well under cold water, dice the bodies, and chop the tentacles.
Open the ink sacks and collect the ink in a small bowl.
Heat the oil in a pot and wilt the garlic without letting it brown. Add the squid, the minced parsley, and a generous dusting of freshly ground pepper. Cover and simmer over low heat for about 45 minutes, checking every now and then to make sure it's not sticking (if it does add a little hot water). Once it has simmered, mix the tomato sauce or paste with the white wine and add it to the pot. Simmer for 20 minutes more, uncovered, then dilute the sauce with a little hot water and simmer for a half hour more, covered. At this point the sauce should be neither soupy nor too dry.
Half an hour before mealtime bring 3 litres of water to a boil, salt them, and add the pasta. At the same time stir the squid ink into the sauce, adding the amount that suits your taste. Drain the pasta, season it with the sauce, and serve.