Roast pork with milk (arrosto di maiale al latte)

Roast pork with sweet potatoes. Marcella Hazan's incredibly simple recipe, comprising only of pork butt, milk, salt, and pepper. Slow roasted for two hours, the milk and the drippings form a gravy of coagulated milk clusters. It doesn't look like much, but the milk clusters are incredibly rich. Divine, even.

Arrosto di maiale al latte (Bolognese origin), adapted from Marcella Hazan's Essentials of Classic Italian Cooking:

1 tablespoon butter
2 tablespoons vegetable oil
2.5 lbs pork rib roast or 2 lbs of Boston butt
Salt
Fresh ground black pepper
2.5 cups whole milk

Do not have any fat trimmed away from either cut of meat. Most of it will melt in the cooking, basting the meat and keeping it from drying. When the roast is done, you will be able to draw it off from the pot and discard it.

1. Choose a heavy-bottomed pot (e.g. enameled cast iron) that can snugly accomodate the pork. Put in the butter and oil, turn on the heat to medium high. When the butter foam subsides, put in the meat, the side with fat facing down at first. Brown the meat well on all sides. If the butter becomes very dark, lower the heat.
2. Add salt, pepper, and 1 cup milk. Add the milk slowly so it does not boil over. Allow milk to come to a simmer for half a minute, turn the heat down to a minimum, and cover the pot with lid on slightly ajar.
3. Cook at very lazy simmer for approx. 1 hour, turning meat occasionally, until the milk has thickened, through evaporation, into a nut-brown sauce. The exact time will depend on heat and size/thickness of pot. When milk reaches this stage, add 1 more cup of milk. Let simmer 10 minutes, then cover the pot tightly with the lid.
4. After 30 minutes, set lid slightly ajar. Continue to cook at minimum heat, when there is no more liquid milk in the pot add another 1/2 cup of milk. Continuing cooking until meat feels tender and all the milk has coagulated into small nut-brown clusters. Altogether it will take 2.5 to 3 hours. If, before the meat is fully coooked, you find that the liquid in the pot has fully evaporated, add another 1/2 cup of milk and repeat above step.
5. When the pork has become tender and all the milk in the pot has thickened into dark clusters, transfer the meat to a cutting board. Let sit a few minutes, then cut into slices.
6. Tip the pot and spoon off the fat, saving the milk clusters. Add 2-3 tablespoons of water and deglace the pot. Spoon all the pot juices over the pork and serve immediately.

I had two smaller chunks of pork butt, thus my meat finished before the milk sauce. If this happens, remove the meat and simmer the milk alone. My pork wasn't especially fatty, so I kept the drippings and used it and the milk bits as my gravy. Richly delicious.