Soak the bread in a bowl with the milk and nutmeg for about 10 minutes until the milk is absorbed. Mash with a fork. Combine the beef, pancetta or bacon, onion and half the garlic in a large bowl. Add the Parmesan, egg and bread. Season with salt and pepper. Mix gently with your hands until well combined. Form into a loaf shape. Spread the breadcrumbs out on a large plate and roll the meatloaf over to coat thoroughly.
Heat the oil in a shallow saucepan with a tight-fitting lid over a medium heat. Add the meatloaf and cook, turning occasionally, until golden all over. Add the wine, boil rapidly until reduced by half, then add the tomatoes. Cover and simmer very gently, turning the meatloaf occasionally and adding a little water if necessary, for 40–45 minutes, or until a knife inserted into the centre comes out hot.
Lift on to a serving dish. Stir the orange rind, parsley and remaining garlic into the pan and simmer for 2 minutes. Season with salt and pepper. Spoon over the meatloaf.