OK, here goes on blackfish chowder. First off, I'm kinda a semi-pro cook, so I never deal in formal written recipes - neither did your Mom or Grandma. There's at least three types of fish chowder I make, but let's start with an Italian-style.
Stock-
You can use canned chicken stock or some clam broth or even fish-flavor bullion cubes, but homemade is the best. Put blackfish heads and frames in a large chowder pot. You have already removed the gills and any blood. Add two big onions, sliced, and about a half bunch of celery. Some salt, pepper, a handful of parsley and a few chopped up carrots. Cover with water, bring to a boil, then simmer for about an hour. Cool and strain through a fine mesh strainer. Pick all the meat from the heads and save. You'll be stunned to see how much good meat you've been throwing out with those blackfish heads all these years!! Throw out all the vegies, bones and stuff. This strained stock is the basis for your chowder and can be frozen if you want to save it or have extra. At this point, it should already taste pretty good.Wash and dry the pot.
Chowder-
Slice or chop about three nice-sized onions, and a few cloves of garlic if you like Cook in a little good olive oil in the pot until soft but not brown. Once again, add about 1/2 to 1 lb carrots, peeled and diced. Add about 1/2 to 1 stalk celery, diced. Add stock to about half fill the pot. Toss in a good handful of minced Italian parsley. Add some oregano and a bit of thyme and sage if you like. Simmer till the vegies are nearly done, then add two 14 oz cans (drained) of chopped tomatoes. Simmer another 1/2 hour, then add the reserved meat from the heads. If you like it meatier, add extra cubes of filleted tog about ten minutes before. Adjust the seasoning to your taste. Remove from heat and let sit covered for ten minutes before serving. Some folks now add cooked macaroni (shells, elbows, whatever) to the pot to make a real one-dish meal.
These instructions may not be like the fancy detailed printed recipes, but everyone who is a real cook varies the proportions and seasonings to their taste. Some good crusty semolina bread, a nice glass of vino on the side and you're in business. Mangia!!