Instructions
Preheat your oven to 160°C (140°C fan, gas mark 3) to prepare the perfect environment for a slow and gentle cook. In a heavy-bottomed casserole, pour in 1 tablespoon of ground nut oil and bring it to a warm shimmer. Generously season your lamb shanks with salt and pepper, then carefully brown them two at a time, ensuring each side develops a deep, golden crust for extra flavor. Add the remaining tablespoon of oil for the second batch to prevent sticking. Once browned, remove the lamb shanks and set aside. Into the same pot, toss in the chopped onions and fry them briskly for about 30 seconds, stirring often to caramelize their edges slightly. Add the chopped ginger, garlic, and red chilli, then reduce the heat slightly and cook for another minute to release their aromatic oils. Sprinkle in 1 tablespoon of brown sugar and stir well to caramelize alongside the spices. Introduce the star anise and bruised lemongrass stalks to the pot, followed by the lamb stock and tomato purée. Season with salt and pepper, then bring the mixture to a rolling boil. Return the lamb shanks to the casserole, cover snugly with a lid, and transfer to the oven. Let the lamb cook slowly for 1½ hours, allowing it to become tender and infused with the fragrant broth. After this initial cook time, add the peeled, roughly chopped sweet potatoes around the shanks, then cover and continue cooking in the oven for another hour. The sweet potatoes will soften beautifully, absorbing the rich flavors while the lamb becomes fall-off-the-bone tender. Once cooked, remove the casserole from the oven. Stir in the fish sauce, lime juice, and 1 teaspoon of brown sugar to brighten and balance the flavors just before serving. To finish, scatter fresh mint, basil leaves, and the thinly sliced red chilli over the dish for a pop of fresh color and a delightful herbal fragrance. Serve hot, ideally with steamed jasmine rice or crusty bread to soak up the luscious sauce. Tip: Browning the lamb shanks well in batches is key to developing deep flavors, so don’t rush this step. Also, gently bruise the lemongrass stalks before adding them to release more aroma during cooking.
