Simmer half a pint of milk with black pepper, fish stock, skin and bones for 20 minutes. Skim and remove the skin and bones, then strain through a chinois. Bring the liquor back to a gentle simmer. Add cubes of smoked cod, smoked haddock, cod fillet and salmon fillet, simmering in the liquor for 5 minutes with a splash of double cream, knob of butter and a glug of sherry. Drain and put the fish into an ovenproof dish. Skim and strain the liquor again.
Fry a chopped shallot or onion with sliced mushrooms and chopped celery in butter, Add paprika and ground white pepper and cook until the onion is transparent but not browned
Reduce the remaining liquor a little, then add to the fried onion/celery/mushrooms and thicken with more cream (and some cornflour if necessary). Add chopped parsley, then pour the sauce over the fish. Top with dill weed.
Mash some boiled potatoes with roughly-chopped steamed parsnips and carrots. Add cream, sea salt, butter and pepper. Dot the mash on top of the fish, leaving the surface ragged and rough. Bake at 200-220C until bubbling and browned on top.