Scrub the clams and cook in a large pan with water until open.
Drain clams while reserving the liquor and cut the meat into 1cm pieces.
Melt butter in a pan and fry the pork or bacon until browned.
Add onions to the pan and fry until softened.
Simmer potatoes in milk, cream, and bay leaf until firm but cooked.
Add the pork, onions, and reserved clam liquor to the potato mixture and simmer for five minutes.
Add the cod fillets and simmer until the fish is cooked.
Stir in the clams, warm through, and season with salt and white pepper.
Serve in a tureen garnished with parsley and crushed biscuits.