Heat the olive oil in a heavy, metal baking dish on a hotplate over medium-high heat. Toss shanks with flour to coat well; then shake off excess. Sear the shanks in hot oil until well browned on all sides, then remove from the dish and set aside.
Add the leek, celery, carrot, onion and garlic to the baking dish. Cook until softened and lightly browned, stirring constantly; about 5 minutes.
Season with the bay leaf, peppercorns, thyme and rosemary sprigs. Pour in the red wine and chicken stock, increase heat to high and bring to a simmer.
Season to taste with sea salt and place the lamb shanks on top of the vegetables.
Cover the baking dish tightly with foil and place into the preheated oven. Bake gently until the meat is tender and falls off of the bone, 2 1/2 to 3 hours.
Remove the bay leaf and herb stems before serving shanks with vegetables and sauce.
Oh my goodness, this was just devine! So simple, yet, so delicious! I can't wait to cook this agian for friends and family. Thanks for sharing. Ps, It is easy to adjust this for the slow cooker so it can cook while at work. - 11 Apr 2012