Ragu Bolognese by Mario Batali

Heat the olive oil over medium heat until hot. Add the onions, celery, carrots, and garlic and cook until the vegetables are translucent but not browned, about 5 minutes. Add the veal, pork, and pancetta, increase the heat to high, and brown the meat, stirring frequently. Add the tomato paste, milk, wine, and thyme and bring just to a boil, then reduce the heat to medium-low and simmer for 1 to 1 1/2 hours. Season the ragu with salt and pepper, remove from the heat, and let it cool. The ragu can be refrigerated for up to 2 days. It can also be frozen for up to 1 month.