2 large carrots, cut into chunks
2 onions, sliced
salt and pepper
500g/1lb 2oz potatoes, cut into large chunks
small bunch thyme
1 bay leaf
1 litre/1戮fl oz beef stock
1 tbsp vegetable oil
1 free-range egg, lightly beaten
400g/14oz puff pastry
1 kg/2lb 4oz neck of lamb, on the bone