Render the Pancetta (Flavor Base): Place pancetta or bacon in a heavy Dutch oven over medium heat. Cook slowly, stirring, until fat renders and meat is lightly golden but not crisp, about 8–10 minutes. If there is excessive fat, remove a small amount, leaving 2–3 tablespoons in the pot.

Build the Soffritto (The Sweet Foundation): Add onion, celery, and carrots. Season lightly with salt. Cook over medium-low heat, stirring frequently, until very soft, fragrant, and slightly sweet — 12–15 minutes. No browning. Add garlic and cook 1 minute more.

Brown the Meats Properly: Increase heat to medium. Add ground beef, turkey, and pork sausage in stages. Break up very finely with a wooden spoon. Cook until all moisture evaporates, meat sizzles in its fat, light browning develops, and no visible pink remains. This takes 12–15 minutes.

Deglaze with Wine: Add white wine. Scrape up any fond. Simmer until nearly evaporated, 5–7 minutes.

Add Milk (Optional but Traditional): Pour in milk. Simmer gently until mostly absorbed and reduced, about 10 minutes.

Tomatoes & Long Simmer: Stir in crushed canned tomatoes, tomato passata, tomato paste, bay leaf, and Parmigiano rind (if using). Reduce heat to very low. Simmer uncovered or partially covered for 2½ to 3 hours, stirring occasionally.

Finish: Remove bay leaf and cheese rind. Stir in butter for silkiness. Taste and adjust seasoning.