Vietnamese lamb shanks with sweet potatoes

1. Heat the oven to 160C/140C fan/gas 3. Heat 1 tbsp oil in a heavy-bottomed casserole, season the shanks, then brown them two at a time on all sides, adding the rest of the oil for the second batch. Lift out the lamb and add the onions. Fry them fairly briskly for about 30 seconds, add the ginger, garlic and chopped chilli, then drop the heat and cook for 1 minute. Stir in 1 tbsp sugar, then add the star anise, lemongrass, stock, purée and seasoning, and bring to the boil.
2. Cover and cook in the oven for 1½ hours, then add the sweet potatoes and cook for another hour. The lamb should be completely tender and almost falling off the bone. Stir in the fish sauce, lime juice and 1 tsp sugar to lift the flavour, then scatter over the mint, basil and sliced chilli to serve.

Tips from the ZestyPlate Kitchen

• Brown the shanks thoroughly before braising for a deeper, richer pot.
• Keep it low and slow until the meat is on the edge of falling off the bone.
• Slip the sweet potatoes in partway through so they take on flavour without collapsing.
• Lift the rich broth at the end with lime, fish sauce and a handful of herbs.