01 - Heat olive oil and butter in a large heavy-bottomed pot over medium heat. Add chopped onion, diced carrots, and celery, sautéing for 6 to 8 minutes until soft and translucent.
02 - Stir in minced garlic and cook for 1 minute until fragrant.
03 - Add ground beef, breaking it apart with a wooden spoon. Cook until browned and no longer pink, approximately 8 minutes.
04 - Stir in tomato paste and cook for 2 minutes to develop depth of flavor.
05 - Pour in red wine, scraping the bottom of the pot to deglaze. Simmer until nearly evaporated, around 2 to 3 minutes.
06 - Mix in crushed tomatoes, beef broth, whole milk, oregano, basil, bay leaf, and nutmeg. Stir thoroughly to combine.
07 - Bring to a gentle simmer, then reduce heat to low. Partially cover and cook for 1½ to 2 hours, stirring occasionally until sauce thickens and flavors meld.
08 - Season with salt and black pepper to taste. Remove bay leaf before serving.
09 - Ladle sauce over freshly cooked pasta such as tagliatelle or use as a filling for lasagna.