Carbonara is the name of an italian pasta dish made with a sauce of eggs, cheese and cooked bacon. There are no specific rules about what type of pasta although fettuccini or linguine are common choices because the raw egg sauce needs pasta with a large surface area to properly adhere. Likewise, the choice of cheese is optional with parmesan and pecorino romano the two types most likely to be used. Some recipes call for whole eggs, others for egg yolks and some combine the two. Pancetta can be substituted for the bacon and chicken is a common addition. Some recipes also include vegetables such as peas, broccoli or even mushrooms. The bacon fat is the source of the oil used to cook the shallots or onions and garlic. If adding chicken, it too gets cooked in the same pan with the bacon fat. Hot pasta water is used to slowly temper the egg and cheese mixture to prevent the eggs from scrambling and they are then added into the hot pasta to create the classic carbonara sauce. It's a simple yet hearty dish that uses ingredients usually on hand.