Heat oil in a frying pan. Add the onion and stir over low heat until tender.
Add the sausage to th epan and cook, turning frequently, for 2-3 minutes. Add the tomato, wine, chili and salt and pepper to taste, and stir. Bring to the boil, reduce the heat and simmer for 15-20 minutes.
While sauce i cooking, cook th erigatoni in a large pan of rapidly boiling salted water until al dente. Drain and return to the pan. Add the sauce to the hot pasta. Toss well to combine. Serve sprinkled with the combined fresh parsley and grated parmesan.