1. In a large ovenproof pan or casserole, heat a little olive oil, season the shanks and seal the meat until brown all over. Remove from the pan, then add the shallots.
2. Cook until the shallots are browned, 2-3 minutes, then reduce the heat, add the harissa paste, cumin, paprika, all spice and garlic, fry for 30 seconds with the shallots, then add the tomatoes, coriander, mint and chicken stock.
3. Bring to the boil, add the lamb shanks, then cover the pan or casserole and braise for 2 hours in the oven until the lamb is soft and tender.
4. Remove the lamb shanks and shallots and keep them warm.
5. Bring the cooking liquor to the boil and reduce until it has the consistency of a good thick gravy. Adjust the seasoning, then add the lamb and shallots back to the sauce and serve with a pea couscous.