Put all the herbs leaves (and the dried oregano) in a mortar with the salt, some pepper, and the oil and grind everything together. Score the fat of the lamb – without cutting the meat – and rub the herb mixture all over it, pushing it down into the slashes.
Scatter the rest of the rosemary, the thyme sprigs and all the garlic cloves in the bottom of a roasting tin (which should hold the lamb shoulder snugly) and set the lamb on top, keeping the garlic and herbs underneath the lamb.Squeeze the lemon on top. Pour half the wine into the tin. Cover the lamb with a double layer of foil, sealing it tightly round the edges.
Put into the oven and immediately reduce the heat to 150C/140C fan*/gas mark 2 and cook for 3½-4 hours. Check every so often to see whether you need to add any more wine (you just need enough to keep the pan moist). The meat is ready when it is falling off the bone.
When there is just 30 minutes of cooking time left, drizzle the honey on top. Once it’s cooked, lay some towels over the foil and leave the lamb to rest for 15 minutes.
To make the relish, remove the lemon zest with a zester, then chop roughly. Peel the white pith away from the lemon and carefully remove the segments by running a very sharp knife down either side of the membranes. Chop the lemon flesh into little pieces and put in a bowl with the zest, olive oil, honey, white balsamic and lemon juice.
Drain and rinse the capers and pat them dry. Chop them and add them along with the garlic. Stir everything together and taste for balance (remember this will be served with fatty lamb – it can take a relish that is assertive and quite acidic). Just before you are about to serve, add the mint leaves to the relish.