Preparation

• Add the dried mushrooms to a small bowl and cover with very hot water; let sit for 15 minutes, then drain and finely chop. In a large bowl, mash the bread and milk together until a smooth paste forms. Gently knead in the beef, salt, and pepper, and mix well.
• Add the butter to a medium-size, heavy saucepan and heat over medium-high heat. When melted, add the pancetta and sauté until browned, about 8 minutes. Pour off all but about 2 Tbs. of the fat. Add the meat mixture, and cook until browned, about 10 minutes. Add the fresh porcini and cook until softened, about 2 minutes. Stir in the dried mushrooms, carrots, celery, onions, garlic, and nutmeg. Sauté until the vegetables are slightly softened and aromatic, about 3 minutes. Add the tomato paste and flour, and cook until the flour is no longer visible, no more than 1 minute. With the pan off the heat, carefully add the wine. Then return the pan to high heat and stir well, scraping the bottom of the pan with a wooden spoon to release any food bits. Cook for 2 minutes, then stir in the tomatoes and stock, and cook for another minute. Pour into the slow cooker.
• Cover the slow cooker and cook on low until the meat has cooked through and the sauce is aromatic and very flavorful, about 6 hours. Spoon the fat off the surface, stir in the rosemary, break up the meat more with a fork, and serve with pasta.