Boil a salted pot of water for your pasta and cook it al dente according to package directions.
In a large bowl flake the tuna and add the Parmesan, lemon zest, parsley, and plent of black pepper.
Once the pasta is done, add a generous splash of the pasta water (a couple tablespoons) to the tuna mix and follow immediately with the spaghetti. Stir quickly.
Add the Worcestershire sauce and the oil, stir again and check the seasoning. You probably won’t need the salt.