1:Part cook the joint of lamb for about 1hr 30m on a low setting (about 100c)
2: after 1 hr of lamb cooking, boil your 3 large spuds
3: when spuds are cooked, mash them with a knob of tbspn of butter/marge and salt/pepper
4:remove lamb from oven. drain juices into saucepan
5: cut up lamb into 1cmish cubes and place bone into the same saucepan you put ur juices in.
6: place diced lamb into a 2" deep baking tray.
7: crumble 4 oxo into pan with bone and juices in and add ale. add salt/pepper and finely chopped onion. bring to the boil and leave to simmer for about 20minutes (u can add corn flour to thicken in you need to)
8: while stock is simmering, add self raising flour (a little at a time) to your mashed spuds. keep adding until you have a pastry consistency, when you do, wrapping ball of dough in cling film and stick it in the fridge
9. remove stock from heat and remove bone.
10 pour stock over the lamb in the baking tin making sure all lamb is coated. then crumble an oxo over the top.
11. cover with tin foil and leave in the fridge for as long as you want.
12: remove meat and pastry from the fridge, flour a worktop and roll out the pastry to cover your tin. cut off excess and use to make letter to place on top of pastry (perhaps a swear word, as these always go down well with guests)
13 cook at the bottom of the oven for 40-50 mins at 180c