Drain the tuna and put in a large serving bowl. Break up with a fork, then stir in all the remaining ingredients, except the pasta and rocket. Season with salt and pepper, cover and leave in a cool place for at least 30 minutes for the flavours to mingle.
Meanwhile, cook the pasta in a large saucepan of salted boiling water according to the packet instructions until al dente.
Drain the pasta, then toss with the rocket into the tuna mixture. Serve immediately, with the bottle of extra virgin olive oil for anyone to drizzle a little oil on to their serving if they like.