1 Heat Olive Oil In A Large Skillet On Medium Heat. Add The Onions And Cook Until Translucent, About 5 Minutes. Add The Garlic And Cook A Minute More. 2 Add The Tomatoes To The Pan, Shredding Them With Your Fingers As You Add Them To The Pan. Include The Juices. Add The Sausage And Red Pepper Flakes. Cover And Cook On Medium High For 20 Minutes, Until The Sauce Is Thickened. 3 While The Sauce Is Cooking, Cook The Pasta. Bring A Large Pot Of Water To A Boil, Add A Teaspoon And A Half Of Salt For Every Quart Of Water. Cook The Pasta According To Pasta Package Instructions, Until Al Dente, Or Cooked Through, But Still A Bit Firm. Drain The Water From The Pasta. Combine The Pasta And The Sauce In A Large Serving Bowl. 4 Stir In The Cubed Smoked Mozzarella Cheese. Continue To Stir Until The Cheese Has Softened And Is A Bit Melty. Sprinkle With Parmesan Cheese.