Bolognese sauce is a meat-based sauce in Italian cuisine, typical of the city of Bologna. It is customarily used to dress tagliatelle al ragù and to prepare lasagne alla bolognese.
Italian ragù alla bolognese is a slowly cooked meat-based sauce, and its preparation involves several techniques, including sweating, sautéing and braising. Ingredients include a characteristic soffritto of onion, celery and carrot, different types of minced or finely chopped beef, often alongside small amounts of fatty pork. White wine, milk, and a small amount of tomato paste or tomatoes are added, and the dish is then gently simmered at length to produce a thick sauce.
Outside Italy, the phrase "Bolognese sauce" is often used to refer to a tomato-based sauce to which minced meat has been added; such sauces typically bear little resemblance to the Italian ragù alla bolognese, being more similar in fact to the ragù alla napoletana from the tomato-rich south of the country. Although in Italy ragù alla bolognese is not used with spaghetti (but rather with flat pasta, like tagliatelle), so-called "spaghetti bolognese" has become a popular dish in many other parts of the world.(where?)