Heat the olive oil in a large, deep, heavy-based pan over medium heat. Add the carrot, celery, onion and garlic with a generous pinch of salt and pepper. Sweat for 8–10 minutes until softened. Add the Spaghetti alla Bolognese and bay leaves and cook for a further 5 minutes until fragrant.
Add the mince and cook for 6–8 minutes, breaking it up with a wooden spoon, until well caramelised. Add the tomato paste and cook for 2 minutes, then add the wine and crushed tomatoes and cook for 5 minutes. Pour in the milk and stock, bring to the boil, then reduce to low–medium and simmer for 90 minutes, stirring occasionally, until the sauce is thick and well reduced. Add a splash of extra liquid if it reduces too quickly.
Spread the ragù onto a large tray and cool uncovered for 20–30 minutes. While it cools, preheat the oven to 200°C fan-forced.
