In a large skillet, sauté the garlic in the olive oil until golden brown. Puree the tomatoes and add them to the skillet. Add the salt and pepper. Cook on low heat, uncovered for about an hour, or until reduced. Pierce the sausage with a fork, and either fry it in another skillet or cook it under the broiler, until the outside is seared. Place the sausage into the tomato sauce and let it cook for the remainder of the time that the sauce cooks.
Bring a large pot of salted water to a boil and cook the pasta until al dente. Drain the pasta and place into a serving bowl. Mix in some sauce. Serve immediately with a piece of sausage and a sprinkle of Parmigiano.