Slow Roast Lamb Shoulder

1/2 lamb shoulder
2 tbsp vegetable oil
1 onion, chopped
3 cloves garlic, minced
2 sticks celery, chopped
2 carrots, chopped1 can chopped tomatoes
250ml white wine
2 bay leaves
1 tsp thyme
Salt and pepper

Place the lamb in a large heatproof dish and bake for 20 minutes at 220 degrees centigrade. Meanwhile, heat the oil in a large pan, add the onions and brown, add the garlic and stir for another minute. Add the carrots and celery and continue cooking. Add the wine, bring to the boil and add the tomatoes and herbs. Season with salt and pepper and bring to the boil. Remove the lamb from the oven, pour the tomato mixture over and cover well with foil. Bake for 2 hours at 160 degrees centigrade or until the meat flakes off the bone easily.