Use the best quality sausages you can find for this sauce. They should have a high meat content. Squeeze the sausage meat out of the sausages, and fry it over a gentle heat until the fat begins to run, then raise the heat, and allow the meat to brown. Remove the meat from the pan, leaving a little of the fat behind, and fry a little onion and garlic in it. Stir in a can of chopped tomatoes, cook until most of the liquid has evaporated, and then stir in the cooked sausage meat, a sprinkling of chopped oregano or marjoram and a glass of red wine. Simmer gently for 20–30 minutes. Season to taste, and stir into freshly cooked spaghetti. Serve with freshly grated Parmesan cheese sprinkled over.