Bring a stockpot of water to the boil. Season it generously with salt and cook the spaghetti al dente according to the package directions. When you drain the pasta, reserve 1 cup of the pasta cooking water.

Pre-heat a large sauté pan over medium-high heat. Drizzle a little olive oil into the pan and sauté the shallot and garlic for 1 minute. Stir in the red pepper flakes, oregano, olives and capers. Sauté for another minute. Add the canned tomatoes to the pan while crushing them with your hands. Lower the heat and simmer for about 10 minutes, until the sauce starts to thicken. Stir in the tuna and gently simmer for 5 more minutes. Stir in the half of the chopped fresh parsley. Season to taste with salt and freshly ground black pepper.

Add the cooked pasta to the pan and toss with the sauce. If needed, add some reserved pasta water to loosen the sauce.

Transfer to serving bowls, season with a squeeze or wedge of lemon if desired and top with the remaining parsley and grated Parmesan cheese.