How to Make It
Preheat the oven to 300°. Season the lamb shanks with salt and pepper. Heat 1/4 cup of the olive oil in a large enameled cast-iron casserole. Working in batches, cook the lamb shanks over moderate heat, turning often, until well browned on all sides, about 12 minutes; transfer to a platter.
Pour off any fat from the casserole and add the remaining 2 tablespoons of olive oil. Add the carrots, celery and onions and cook over moderate heat until the vegetables start to brown, about 8 minutes. Stir in the tomato paste, then add the wine, scraping up the browned bits from the bottom. Stir in the bay leaves and peppercorns. Return the lamb shanks to the casserole and add the stock. Bring to a boil, cover and bake the shanks in the oven for about 3 hours, or until the meat is very tender.
Transfer the shanks to the platter and remove the meat from the bones. Put the meat in a bowl and cover with a damp towel. Strain the sauce into a large saucepan, pressing on the vegetables to extract as much liquid as possible. Boil the sauce over high heat until it is thick enough to coat the back of a spoon, about 25 minutes; season with salt and pepper. Return the lamb to the sauce and rewarm over moderate heat.
In a small bowl, mix the parsley with the lemon zest and garlic. Spoon the lamb stew over the Morel and Sweet Pea Risotto, sprinkle with the gremolata and serve.