Heat the oven to 160C/Gas Mark 3. On the hob, heat the oil in a roasting tin that’s large enough to hold the leg. Season the meat and brown it well on all sides — this will take about 10 minutes — then remove from the tin and put to one side.

Put the onions and carrot in the tin and stir for a few minutes until starting to soften, then add the wine and bubble for a minute or two. Replace the meat, adding the garlic, bay leaves and 150ml water. Keep back two of the thyme sprigs, then throw the rest into the tin. Season again, scattering with the chilli flakes, then cover with a double thickness of foil, tucking it in around the outside edge of the tin so the meat is hermetically sealed.

Put in oven and cook for 4½-5 hours. Baste every hour or so, carefully replacing the foil afterwards. When it is done, you should be able to pull the bones from the meat. Carefully lift the joint from the tin onto a board or serving dish and cover with the foil to keep it warm.

Remove most of the fat from the cooking juices and strain the rest of the sauce through a sieve into a saucepan, pressing down to get all the flavour from the vegetables and herbs; you can force some of them through the sieve to thicken the sauce a bit if you want. If the juices are too thin, put the pan on the hob and bubble away for a few minutes, but don’t expect it to be like a thickened gravy. Add a few squeezes of lemon juice to taste — you just want to brighten the flavour of the sauce, not make it overtly lemony. Check the seasoning and reheat if necessary.

Strip the leaves from the remaining thyme sprigs and chop finely. Mix with the parsley and sprinkle over the meat. Serve the lamb in chunks pulled from the bone, with some of the sauce spooned over the top.