In a large saucepan, sweat the chopped carrot, celery and onion in the olive oil. Separately, boil the octopus in boiling water for about 4/5 minutes, take it out and chop it into small pieces. Then put the octopus in the saucepan with the vegetables and sauté for a few minutes before adding the white wine. Let the wine evaporate and then add the diced tomatoes and the bay leaf. Simmer at a very low heat for about 2 hours and then take out the bay leaf. Cook the pasta separately in plenty of salted boiling water, drain and add to the octopus sauce. Serve the malfaldine garnished with a leaf of basil.