How to Make It
Preheat the oven to 325°. In a large enameled cast-iron casserole, heat the peanut oil. Season the pork with salt and pepper. Add the shanks to the casserole and cook over moderate heat, turning, until browned all over, about 20 minutes; transfer to a plate.
Add the onion to the casserole and cook over moderate heat, stirring occasionally, until golden, about 4 minutes. Stir in the water, miso, brown sugar, soy sauce, ginger, garlic, chiles and scallions. Add the shanks and any juices and bring to a boil. Cover and braise in the oven for 2 hours, until the pork is very tender. Garnish with scallions and serve with rice.