In a heavy enameled cast-iron Dutch oven over medium heat, render 150g finely minced pancetta for 6 to 8 minutes until translucent and aromatic. Add finely diced onion, carrot, and celery. Sweat gently over medium-low heat for 12 minutes until vegetables soften into a sweet soffritto without browning.

Turn heat up to medium. Add 500g ground beef chuck, breaking it apart with a wooden spoon. Cook gently for 8 to 10 minutes until the meat turns from pink to pale grey-brown. Do not crisp or deeply sear the meat; traditional Bolognese relies on soft, tender braised morsels.

Pour in 150ml crisp dry white wine. Scrape any delicate pan fond from the base. Simmer vigorously for 8 minutes until alcohol evaporates completely and liquid has reduced by 90%.

Pour 250ml whole milk into the simmering meat and add a generous pinch of freshly grated nutmeg. Reduce heat to low and simmer uncovered for 15 minutes until milk has reduced into creamy curds that coat the meat fibers.

Stir in 60g double concentrated tomato paste dissolved in 150ml warm beef broth. Partially cover the Dutch oven with lid slightly ajar. Maintain the gentlest bare simmer (occasional bubble breaking the surface) for 2.5 to 3 hours, adding remaining broth 50ml at a time whenever the sauce dries out. Finish with salt and pepper.

Boil fresh egg tagliatelle in salted water for 3 minutes until al dente. Toss pasta directly into the ragu with a ladle of pasta water and a dollop of butter. Serve in wide bowls topped with freshly grated 24-month Parmigiano-Reggiano.