Put the beans into a large bowl, cover with plenty of fresh cold water and soak for 12 hours or overnight.
Preheat the oven to 200. C fan
Sit the lamb shoulder in a large, deep roasting tray. Trickle over half the olive oil and season generously with plenty of salt and pepper.
Place in the hot oven for 25–35 minutes so that it takes on some colour.
Peel and slice the onions and scatter them around the lamb.
Add the drained soaked beans, the wine or cider, the halved garlic bulb, the thyme, rosemary and bay.
Pour in about a litre of water (you can use stock if you prefer, but there’s so much flavour in the lamb it’s not essential)
Turn the heat down to 150. C
Cover the lamb and beans with parchment or foil, and return to the oven. Set the tray in the middle of the oven and cook slowly, stirring once or twice, it’ll take 3 – 4 hours.
After the allotted time, take the lamb out of the oven, both the beans and the meat should be exceptionally tender. Stir in the nettles as best you can. Cover and return to the oven for a further 20 minutes.
During this time the nettles will wilt down beautifully. Remove the tray from the oven And allow everything to rest for 15 – 20 minutes.
When you’re ready to serve, uncover and season the beans and nettles to taste with salt and pepper and stir in the vinegar.
Serve the lamb with the beans and nettles some good bread, and a nice sharply dressed green salad.