Sweat the chopped onion and garlic in a pan with a little olive oil until translucent and then add the whole sausage. When well browned add the tomato paste, the drained peeled tomatoes, a pinch of salt and freshly grated pepper.
Bring the sauce to a boil and add 3/4 cup of hot water. When simmering, cover and let cook for about 40 minutes over a moderate flame.
Cook the pasta separately in a large pot of salted boiling water and drain it when it is still "al dente," firm to the bite, about 8 minutes.
Return the pasta to the pot and stir in the sauce, the steamed brussel sprouts and the diced Asiago cheese. Pour into a buttered baking dish. Sprinkle with dabs of butter and the grated sharp Asiago cheese.
Place in a hot oven at 450°F for 15 minutes. Serve the pasta straight from the oven dish.
Serves 4.
