Raise the heat slightly to medium or medium-high and add the tomatoes and oregano. cook rapidly, stirring frequently, until the tomato juice has evaporated and the tomatoes are reduced to a jam, about 20 minutes. Taste for seasoning.
While the sauce is cooking, bring a large pot of salted water to a boil and cook the pasta until tender but still firm. Drain the pasta and turn into the sauce. Remove from the heat and toss to coat the pasta with sauce. Sprinkle with the remaining parsley and serve immediately passing the pepper mill at the table.