Try to get your fishmonger to skin and gut the squid for you. Score the squid lightly in a casual criss-cross fashion. Set it aside while you get a griddle pan very, very hot. You can also use a wok or the barbecue.
Season the squid lightly with salt and pepper just before cooking, then add it to the pan. After a minute, it should be nicely charred, so turn it over and cook for a further minute. Remove the squid from the pan and set aside.
Heat up the cannellini beans and sprinkle them into a bowl. Add the sliced chiles to the bowl with the rocket, lemon juice, and olive oil, and season. Cut the squid at irregular angles and toss it in with the rest of the ingredients. A good drizzle of extra-virgin olive oil over the top will finish it off nicely.