Ragù Classico alla Bolognese

A combination of several different kinds of meat, chopped with a heavy knife, is fundamental to this version of a classic pasta sauce, which uses only a tiny amount of tomato paste rather than canned tomatoes to give it sweetness and colour. Long cooking time over a very low heat is essential and this is one sauce that improves after being left for a day and then reheating. Serve it with tagliatelle for a truly authentic ragù alla Bolognese.