Prep the base: Warm 1 tablespoon olive oil and 1 tablespoon butter in a large pot over medium heat. Add onion, carrot, and celery with a pinch of salt.
Cook 6–8 minutes until soft and lightly golden. Stir in garlic for 30 seconds.
Brown the meat: Add ground beef and pork. Break it up with a spoon and cook until well browned, about 7–10 minutes.
Season with salt and pepper. Don’t rush—browning builds flavor.
Tomato paste and deglaze: Stir in 2 tablespoons tomato paste and cook 2 minutes to caramelize. Pour in 1/2 cup red wine, scraping up any browned bits.
Let it reduce by half.
Simmer the sauce: Add crushed tomatoes, 1 bay leaf, 1 teaspoon dried oregano, and a pinch of nutmeg. Bring to a gentle simmer, then reduce heat to low. Cook uncovered 30–45 minutes, stirring occasionally, until thick and glossy.
Finish with milk: Stir in 1/2 cup milk and simmer another 5–10 minutes.
Taste and adjust salt and pepper. Remove bay leaf.
Cook the pasta: Boil spaghetti in well-salted water until just al dente. Reserve 1/2 cup pasta water, then drain.
Bring it together: Toss pasta with a few ladles of sauce and a splash of pasta water to help it cling.
Plate and top with extra sauce, Parmesan, and herbs.