Remove from oven and set aside. Turn oven to 180 degrees Celsius.
Meanwhile, chop the onions and garlic finely.
Peel and slice the carrots into discs.
Heat some olive oil in a heavy based pan.
Fry the onions and garlic til translucent.
Add the lamb and brown.
Add the cinnamon, cardamom powder, coriander powder, cayenne pepper and paprika and coat the lamb pieces.
Add the jar of passata and the red wine and bring to boil.
Add the carrots.
Add the bayleaf and parsley.
Simmer on a very low heat for several hours until the lamb is very tender and falls apart in the stew. Keep checking regularly, stirring, and adding water if necessary. (The end result has to be a thick stew).
To make the white sauce, melt the butter in a saucepan.
Add the flour and stirfry for a minute or two.
Remove from heat and slowly stir in milk.
Add all the cheese and return to heat.
Slowly heat until thickened.
Add the egg, cook for a further few minutes.
Add the nutmeg and some salt and pepper to taste and then remove from heat.
To assemble the dish, pour the ragu into the bottom of a casserole dish.