Heat oven to 160C/fan 140C/gas 3. Heat some dripping or butter in a large shallow casserole dish, brown the lamb in batches, lift to a plate, then repeat with the kidneys.
Fry the onions and carrots in the pan with a little more dripping until golden.
Sprinkle the flour over, allow to cook for a couple of mins, add the Worcestershire sauce, pour in the stock, then bring to the boil.
In an oven-proof bowl layer the meat and bay leaves, then onions/carrots then more meat, etc..
Arrange the sliced potatoes on top then drizzle with a little more dripping or butter.
Cover, then place in the oven for about 1½ hrs until the potatoes are cooked.
Remove the lid, brush the potatoes with a little more dripping or butter, then turn the oven up to brown the potatoes, or finish under the grill for 5-8 mins until brown.
