here's the recipe:
500g (18 oz) tagliatelle
15g (1/2 oz) dried porcini mushrooms (optional)
60 g (2 oz) unsalted butter
60g (2 oz) streaky unsmoked bacon, finely chopped
40g (l'/2 oz) celery, finely chopped
40g (1/2 oz) carrot, finely chopped
a small onion or shallot
300g (11 oz) excellent beef mince
1½ tumblers good red wine
nutmeg, grated
1½ teaspoons plain flour
2 scant teaspoons tomato paste
a little broth
good Parmesan cheese, grated
Soak the porcini for an hour in a little warm water, if using. Melt three quarters of the butter in a casserole with the bacon. When the bacon begins to colour add the celery, carrot and chopped onion and let them soften gently. Add the beef, and brown it Pour in half the wine and cook briskly to evaporate most of it. Season with salt, pepper and nutmeg, sprinkle with the flour, stir, add the tomato paste, the porcini and a ladle of broth. Cover, and simmer the sauce very slowly for at least l'/2 hours, stirring occasionally and adding a little porcini liquid, strained through a muslin, or some hot broth. Towards the end add 2 tablespoons of milk, to soften the flavour, taste and adjust the seasoning. Have ready a large pan of boiling salted water. Cook the pasta al dente, place on a warm dish, add the remaining butter in little flakes, and top with three-quarters of the sauce - the rest is passed round at table, like the Parmesan.
This is the classic version, but some people add 2 tablespoons of thick cream to the sauce at the very end. In Bologna they also vary the recipe by using half beef, half pork