Place a large pot of water over high heat and bring up to a boil. Salt the water and cook penne to al dente.
Meanwhile, heat a large skillet with 3 turns of the pan extra-virgin olive oil over medium heat. Add the garlic and red pepper flakes, cook a minute or 2, then add tuna and break it up with your spoon. Add olives and capers, cook a minute or 2 more, then add vermouth or white wine; stir and cook down a minute. If using whole tomatoes, place a colander over a bowl, crush up tomatoes with a wooden spoon, then add tomatoes and their juice to pan. Otherwise, stir in diced tomatoes and juice. Add parsley, zest and black pepper, then simmer the sauce a couple of minutes more.
Add a couple of ladles of starchy pasta-cooking water to the sauce. Drain pasta, add to the skillet and toss to coat. Serve with some nice crusty bread.