01 - Heat olive oil and butter in a large heavy-bottomed pot over medium heat.
02 - Add onion, carrot, and celery; sauté for 6 to 8 minutes until softened and translucent.
03 - Stir in minced garlic and cook for 1 minute until fragrant.
04 - Add ground beef and cook, breaking it up with a wooden spoon, until no longer pink, about 8 minutes.
05 - Stir in tomato paste and cook for 2 minutes to deepen flavor.
06 - Pour in red wine, scraping up browned bits from the pot; simmer until nearly evaporated, approximately 2 to 3 minutes.
07 - Add crushed tomatoes, beef broth, milk, oregano, basil, bay leaf, and nutmeg; stir to combine thoroughly.
08 - Bring to a gentle simmer, reduce heat to low, partially cover, and cook for 90 to 120 minutes, stirring occasionally until thick and rich.
09 - Remove bay leaf; season sauce with salt and freshly ground pepper to taste.
10 - Serve over freshly cooked pasta such as tagliatelle or use as a filling for lasagna.