Heat the olive oil in a pan and sauté the onion with the whole garlic clove. When the onion has turned golden brown, add the tomatoes, then season with salt and pepper. Cook the sauce over high heat for about 15 minutes, stirring occasionally.
Add the tuna and cook for another 4 to 5 minutes. Remove the garlic clove, and add the minced parsley and the chopped basil.
Bring a pot of salted water to a boil and cook the fusilli until it is al dente; drain.
Toss the cooked pasta with the tomato sauce, and serve.