Preheat the oven to 220 degrees C. Put the lamb shanks in a large flameproof casserole dish and roast for 25 minutes until they are a rich brown colour on the outside. Drain on paper towel. Reduce the oven temperature to 160 degrees C.
Heat the oil in the casserole dish over a medium heat. Add the shallots and cook for 5 minutes, stirring until lightly browned. Stir in the garlic, rosemary, bay leaf and tomatoes and cook for 1 minute. Stir in the lentils, then add the lamb shanks, pushing them down into the vegetable mixture.
Stir the pomegranate molasses and honey into the stock, then pour over the lamb. Slowly bring to the boil, then cover the casserole dish with a tight-fitting lid and bake for 45 minutes.
Remove the casserole from the oven, add a little more stock if needed and stir in the figs and zucchini (this is easier if you lift out the lamb shanks first, then return them after stirring). Cover and bake for a further 45 minutes or until the lamb is very tender. Lift out the lamb and carve the meat from the shanks. Discard the bones and return the meat to the casserole. Gently stir, then serve scattered with coriander.