Neck of lamb is fatty, so cook it as you would any heavy marbled meat. I don't think it lends itself well to quick cooking.
I actually put my last lot in a stew, Dice it up, and toss it in seasoned flour. Then heat a frying pan with some olive oil until really hot and brown the meat, before putting it into the casserole.
Then brown a load of chopped onion, (one whole one), a couple of sliced carrots, a sliced leek, and a clove of garlic in the frying pan also with more olive oil. Then add either some dark beer (a pint will do, guiness or a bitter like London Pride) or some red wine (a glass will do) and deglaze that pan. Pour the whole lot into the casserole. Top up with some beef or Lamb stock if you need to... the whole thing needs to sit in liquid.
Add some chopped kidneys if liked. Add a good heavy squeeze of tomato puree. Add 2 or 3 strands of fresh Thyme. Add a heavy splash of worcestershire sauce. Add a bouquet garni if you have one.
Cook in a low oven (mark 3) for 2 hours. Turn up the heat to mark 5 and add dumplings for the last 25 mins if you want. To me, they crown a stew.
