Season lamb shanks with salt and pepper. In a large ovenproof pot, heat olive oil over medium-high heat. Brown lamb shanks on all sides, then remove and set aside.
In the same pot, sauté potatoes, carrots, onions, and garlic for a few minutes.
Stir in the tomato paste, cinnamon, allspice, salt, pepper, oregano, and thyme. Mix well and cook for another 2 minutes to blend flavours.
Add the red wine, diced tomatoes, and enough water or beef stock to just cover the vegetables. Give everything a good mix to combine.
Return the lamb shanks to the pot and arrange them evenly over the vegetables. Add rosemary and bay leaves.
Bring the pot to a boil on the stovetop. Once boiling, cover and transfer to a preheated oven at 175°C (fan-forced) for 2 hours.
Remove the pot from the oven, uncover, turn the lamb shanks, and return to the oven for another 30 minutes, uncovered.
Once the lamb is tender, remove it from the oven and let it rest for 10 minutes. Give a gentle mix and allow the sauce to thicken.
Serve the lamb shanks and vegetables on individual plates. Sprinkle with freshly chopped parsley for added colour and flavour, if desired.