The main ingredient in a traditional Bolognese sauce is ground meat, typically a combination of pork and beef. This hearty sauce originates from Bologna, Italy, and is slow-cooked with aromatic vegetables such as onions, carrots, and celery, along with tomatoes, wine, and sometimes milk or cream to create a rich flavor profile. Bolognese sauce is traditionally served with tagliatelle pasta or used in lasagna, highlighting its versatility in Italian cuisine. It reflects the importance of quality ingredients and slow cooking in developing deep flavors.