Boil the pasta according to the instructions in the package. Then heat the oil in a large saucepan and gently toast the onion and garlic. Add the tomatoes, tomato paste, oregano, and sundried tomatoes.
Boil them all for 10-12 minutes. Then add salt and pepper. Add the olives, capers, and tuna to the sauce and finally the prepared pasta and mix them all together. Finally add parmesan and parsley and serve warm.