Prepare the tomatoes and cut them into quarters.
Pour-in the tonno in a large bowl.
Add the tomatoes in cubes.
Mix basil leaves, garlic, salt and oregano. Add olive oil and mix well.
Put in the refregerator for 30 minutes.
Meanwhile, bring a large pot of water to a boil, adding salt and a splash of oil. Cook the pasta al dente. Drain.
Add the pasta to the prepared cold mixture and toss to combine. Serve topped with basil leaves.