Heat olive oil in a large pot over medium-high heat. Add ground beef and sausage, breaking up with a spoon. Cook until browned and caramelized, about 8-10 minutes. Remove meat with a slotted spoon and set aside.
In the same pot, add onion, carrots, and celery. Saute until softened, about 8 minutes. Add garlic and cook 1 minute until fragrant.
Stir in tomato paste and cook for 1-2 minutes to deepen the flavor.
Pour in red wine and scrape up any browned bits from the bottom. Let wine reduce by half, about 3-4 minutes.
Return meat to pot. Add crushed tomatoes, milk, basil, oregano, salt, and pepper. Stir well to combine.
Bring to a simmer, then reduce heat to low. Cover partially and simmer for 90-120 minutes, stirring occasionally. The sauce should be thick and rich. Taste and adjust seasoning.