In a large saucepan, heat olive oil over medium-high heat. Cook chopped onion, carrot, celery and garlic for 10 minutes. Stir often until soften.
Add ground beef and stirring occasionally until the meat is browned all over. Add plum tomatoes, tomato paste, bay leaves, chopped basil, italian seasoning, salt, and black pepper. Breaking up the plum tomatoes and stir until just combined.
Add beef stock and milk, stir until well combine then reduce the heat to low. Cover it with lid and simmer for about 1 hour until the sauce is rich and thicken. Stirring occasionally.
In a large pot boiling salted water, cook tagliatelle pasta until al dente, drain well then stir into the bolognese sauce. Garnish with parmesan cheese before serving.
Enjoy!