Heat a large, deep skillet over medium heat. Add extra-virgin olive oil and garlic to the pan. When garlic speaks by sizzling in oil, add tuna and mash into oil with the back of a wooden spoon. Let the tuna sit in the oil 5 to 10 minutes to infuse the fish flavor into the extra-virgin olive oil and to give the tuna time to break down -- it will almost melt into the extra-virgin olive oil. Raise the flame a bit and add the coarsely chopped tomatoes. Season with salt and pepper. Heat the tomatoes through, 2 minutes, then add hot, drained pasta that has been cooked to al dente. Add parsley to the tuna and pasta and toss to combine well and evenly coat pasta. Adjust seasonings. Top pasta with shredded basil and serve.