Sunday Bolognese with Tagliatelle

Method

1. Cook the pancetta and olive oil in a 5-quart Dutch oven over medium heat for 5 to 6 minutes, until the fat renders and the bits turn pale gold. Add the onion, carrot, celery and 1 tsp salt and cook 10 to 12 minutes, until soft and sweet but not browned, stirring in the garlic for the last minute.
2. Raise the heat to medium-high and add the beef, pork and the second 1 tsp salt, breaking the meat into pea-size crumbles. Cook 12 to 15 minutes, until the liquid has evaporated and the meat sizzles and browns, with a brown crust forming on the bottom of the pot.
3. Add the milk and nutmeg and simmer 8 to 12 minutes, until it is fully absorbed and the pot looks glossy rather than wet.
4. Pour in the wine, scrape up the browned bits, and simmer 3 to 4 minutes, until nearly dry. Stir in the tomato paste and cook 2 minutes, until it darkens to brick red. Add the tomatoes, 1 cup of the broth, the bay leaf and the cheese rind and bring to a bare simmer.
5. Drop the heat to low, set the lid ajar, and cook 2½ to 3 hours, stirring every 30 minutes and adding the remaining broth ¼ cup at a time whenever the surface looks dry. It is done when the sauce mounds on a spoon and a layer of orange fat shimmers on top.
6. Remove the bay leaf and rind, skim off the excess fat, and adjust the salt.
7. Boil the tagliatelle in 4 quarts of water with ¼ cup salt, 1 minute short of the package time. Reserve 1 cup of the water, then drain.
8. Toss the pasta with the ragù, the butter and ½ cup of the pasta water in the Dutch oven or a large pot over medium heat for 1 minute. Serve with the Parmigiano.

Food safety. Cool the ragù within 2 hours. Refrigerate up to 4 days or freeze up to 3 months, and reheat to 165°F.