Cook the octopus for 30-45 minutes in salted water with lemon, bay leaf and sprigs of thyme. Once cooked leave to cool. Meanwhile prepare the dressing. In a medium hot pan add the shallots, garlic and the chopped sweet peppers. Add the tomato paste and cook for around two minutes. Add the white wine and reduce. Pour water and simmer for ten minutes. Finally add the basil and season. Blitz and pass through a fine sieve. Once cooled ,whisk in a little the olive oil. Cut the Octopus discarding the heads. In a bowl toss the octopus, chopped chilli, garlic, lemon Juice and the olives. For a better result, it is ideal to leave to marinate overnight. Serve with mixed salad leaves and drizzle the sweet pepper dressing all over the octopus.