Cut the pork into dice, and chop the onion. Cook till tender, but without browning. Slice the potatoes, which should have been previously blanched, put a layer in a saucepan with a little of the pork and onion, then slices of fish, and continue in alternate layers till the fish, etc., have been used up. Season with salt and pepper. Add about 1 pint of water, cover closely and simmer for about 45 minutes till the fish is tender. Add the biscuits, broken in small pieces, and thin the chowder with a little boiling milk.