How to Make It
Preheat the oven to 300°. In an enameled cast-iron casserole, add the pork, garlic, sage, cream and water. Using a vegetable peeler, remove the zest from the lemon in strips. Add the zest to the casserole. Halve the lemon and squeeze in the juice. Season with salt and pepper; bring to a boil. Cover the casserole and braise the pork in the oven for 3 hours, until the meat is very tender.
Transfer the pork to a plate and pat dry. Strain the liquid into a heatproof bowl and skim off the fat. Return the liquid to the casserole and boil until reduced to 2 cups, 45 minutes. Season with salt and pepper.
Meanwhile, in a large, deep skillet, heat the oil. Carefully add the pork, skin side down, and cook over moderately high heat, turning, until the skin is crisp, 15 minutes; use 2 pairs of tongs to steady the pork. Transfer the pork to a cutting board, skin side up, and slice it 1/4 inch thick. Serve with the gravy.