Preheat the oven to 325 degrees F. Heat the oil in a large skillet. Season the lamb with salt and pepper; brown well on all sides. Set the shanks in a casserole dish. Combine the remaining ingredients in a bowl and then pour over the lamb. Cover and bake the lamb for 2 to 2 1/2 hours, or until it is "falling-off-the-bone" tender. Skim any fat from the surface of the lamb before serving.