Pot-roast Lamb Shoulder with Carrots and Onions

We recently visited friends in Lancaster, and amongst the beautiful dishes they prepared for us was a shoulder of lamb, gently pot-roasted for 22 hours.  It was amazingly tender and delicious.  Sadly, because of the slightly bizarre configuration of our flat, we can't do anything like that, as our bedroom is next to our kitchen - the smell overnight would prevent me from sleeping!  However, you can still achieve something approaching that tenderness and succulence in a shorter time, so this version cooked for 5 hours instead.  You brown a boned, rolled shoulder in some oil in a heavy ovenproof casserole, then add lots of large chunks of onions and some peeled chopped carrots.  Add a couple of bay leaves and some sprigs of thyme and rosemary.  Deglaze the pan with 250ml each of white wine and lamb or chicken stock, and season well with salt and pepper.  Clamp the lid on, with a layer of foil underneath if you doubt its airtightness, and bake in a low oven (around 120C) for 4 to 5 hours.  Check after 3 hours and top up with a bit more wine/stock.  It shouldn't be swimming in liquid, but should have some delicious light juices in the bottom.  When you adjudge it to be tender enough to cut with a spoon, dish up in large chunks (slicing is virtually impossible, it is so soft and melting), with the veg around and spoonfuls of the lovely winey lamby juices.  Creamy colcannon, in honour of St Patrick's Day yesterday, went down well with this, as did some sticky, caramelly roasted parsnips.